THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 

LOS  ANGELES 

GIFT  OF 

John  S.Prell 


STEEL: 


A    MANUAL    FOR    STEEL-USERS. 


BY 

WILLIAM   M  ETC  ALP. 


FIRST   KD1T1DN. 

THIRD    THOUSAND. 


'  P"ELL 


NEW  YORK: 

JOHN   WILEY    &  SONS.     - 
LONDON:  CHAPMAN  &  HALL,  LIMITED. 

1903, 


Copyright,  1896, 

BY 

WILLIAM  METCALF. 


ROBERT  DRUMMONu,  EUX3TROTYPER  ANl>  PRINTER,  NEW  YORK. 


rs 


INTRODUCTION. 


TWENTY-SEVEN  years  of  active  practice  in  the  manufact- 
ure of  steel  brought  the  author  in  daily  contact  with  ques- 
tions involving  the  manipulation  of  steel,  its  properties,  and 
the  results  of  any  operations  to  which  it  was  subjected. 

Blacksmiths,  edge-tool  makers,  die-makers,  machine- 
builders,  and  engineers  were  continually  asking  questions 
whose  answers  involved  study  and  experiment. 

During  these  years  the  Bessemer  and  the  open-hearth 
processes  were  developed  from  infancy  to  their  present 
enormous  stature;  and  the  shadows  of  these  young  giants, 
ever  menacing  to  the  expensive  and  fragile  crucible,  kept 
one  in  a  constant  state  of  watching,  anxiety,  and  more 
study. 

The  literature  of  steel  has  grown  with  the  art;  its  books 
are  no  longer  to  be  counted  on  the  fingers,  they  are  to  be 
weighed  in  tons. 

Then  why  write  another  ? 

Because  there  seems  to  be  one  little  gap.  Metallurgists 
and  scientists  have  worked  and  are  still  working;  they  have 
given  to  the  world  much  information  for  which  the  world 
should  be  thankful. 

Engineers  have  experimented  and  tested,  as  they  never 
did  before,  and  thousands  of  tables  and  results  are  re- 

iu 

733719 


iv  INTRODUCTION. 

corded,  providing  coming  engineers  with  a  mine  of  inval- 
uable wealth.  Steel-workers  and  temperers  have  written 
much  that  is  of  great  practical  value. 

Still  the  questions  come,  and  they  are  almost  always 
those  involving  an  intimate  acquaintance  with  the  proper- 
ties of  steel,  which  is  only  to  be  gained  by  contact  with  both 
manufacturers  and  users.  In  this  little  manual  the  effort 
is  made  to  fill  this  gap  and  to  give  to  all  steel-users  a  sys- 
tematic, condensed  statement  of  facts  that  could  not  be  ob- 
tained otherwise,  except  by  travelling  through  miles  of 
literature,  and  possibly  not  then.  There  are  no  tables,  and 
no  exact  data;  such  would  be  merely  a  re-compilation  of 
work  already  done  by  abler  minds. 

It  is  a  record  of  experiences,  and  so  it  may  seem  to  be 
dogmatic;  the  author  believes  its  statements  to  be  true — 
they  are  true  as  far  as  his  knowledge  goes;  others  can 
verify  them  by  trial. 

If  the  statements  made  prove  to  be  of  value  to  others, 
then  the  author  will  feel  that  lie  has  done  well  to  record 
them ;  if  not,  there  is  probably  nothing  said  that  is  likely 
to  result  in  any  harm. 


CONTENTS. 


CHAPTER   L 

MM 

GENERAL  DESCRIPTION  OF  STEEL,  AND  METHODS  OF  MANU- 
FACTURE.— Cemented  or  Converted  Steel.  Blister,  German, 
Shear,  Double-shear.  Crucible-steel,  Bessemer,  Open- 
hearth 1 

CHAPTER    II. 

APPLICATIONS  AND  USES  OF  THE  DIFFERENT  KINDS  OF 
STEEL.— Crucible,  Open-hearth,  Bessemer 14 

CHAPTER    III. 
ALLOT  STEELS  AND  THEIR  USES. — Self-hardening,  Manganese, 

Nickel,  Silicon,  Aluminum 27 

CHAPTER     IV. 

CARBON. — General  Properties  and  Uses.  Modes  of  Introducing 
It  in  Steel.  Carbon  Tempers,  How  Determined.  The  Car- 
bon-line. Effects  of  Carbon,  in  Low  Steel,  in  High  Steel.  Im- 
portance of  Attention  to  Composition 87 

CHAPTER     V. 

GENERAL  PROPERTIES  OF  STEEL.— Four  Conditions :  Solid, 
Plastic,  Granular,  Liquid.  Effects  of  Heat.  Size  of  Grain. 
Recalescence.  Magnetism.  Effects  of  Cooling,  Hardening, 
Softening,  Checking.  Effects  of  Forging  or  Rolling,  Hot 
or  Cold.  Condensing,  Hammer- refining,  Bursting.  Ranges 
of  Tenacity,  etc.  Natural  Bar,  Annealed  Bar,  Hardened  Bar, 
etc 62 


vj  CONTENTS. 

CHAPTER     VI. 

PAGE 

HEATING.— For  Forging;  Hardening;  Overheating;  Burning;  Re- 
storing; Welding ^ 

CHAPTER    VII. 

ANNEALING ^4 

CHAPTER    VIII. 

HARDENING  AND  TEMPERING.— Size  of  Grain;  Refining  at  Recal- 
escence;  Specific-gravity  Tests;  Temper  Colors;  How  to  Break 

Work;  a  Word  for  the  Workman 90 

CHAPTER     IX. 
EFFECTS    OF    GRINDING. — Glaze,    Skin,    Decarbonized    Skin, 

Cracked  Surfaces,  Pickling 123 

CHAPTER      X. 

IMPURITIES  AND  THEIR  EFFECTS. — Cold-short,  Red-short,  Hot- 
short,  Irregularities,  Segregation,  Oxides,  etc.,  Wild  Heats, 
Porosity,  Removing  Last  Fractions  of  Hurtful  Elements. 
Andrews  Broken  Rail  and  Propeller-shaft 129 

CHAPTER     XI. 

THEORIES  OF  HARDENING.— Combined,  Graphitic,  Dissolved, 
Cement,  Hardening  and  Non-hardening  Carbon.  Carbides. 
Allotropic  Forms  of  Iron  a,  /I, etc.  Iron  as  an  Igneous  Rock 
or  as  a  Liquid 146 

CHAPTER    XII. 

INSPECTION.— Ingots,  Bars,  Finished  Work.  Tempers  and  Sound- 
ness of  Ingots.  Seams,  Pipes,  Laps,  Burns,  Stars. 151 

CHAPTER      XIII. 
SPECIFICATIONS.— Physical,    Chemical,    and  of   Soundness  and 

Freedom  from  Scratches,  Sharp  Re-entrant  Angles,  etc 154 

CHAPTER    XIV. 
HUMBUGS 161 

CHAPTER    XV. 
CONCLUSIONS  . , , .  164 

GLOSSARY. 
DEFINITIONS  OF  SHOP  TERMS  USED..  . .  , .  1C7 


STEEL: 
A  MANUAL  FOR  STEEL  USERS. 


GENERAL  DESCRIPTION  OF  STEEL  AND  OP 
MODES  OF  ITS  MANUFACTURE. 

STEEL  may  be  grouped  under  four  general  heads,  each 
receiving  its  name  from  the  mode  of  its  manufacture;  the 
general  properties  of  the  different  kinds  are  the  same, 
modified  to  some  extent  by  the  differences  in  the  operations 
of  making  them;  these  differences  are  so  slight,  however, 
that  after  having  mentioned  them  the  discussion  of 
various  qualities  and  properties  in  the  following  pages  will 
be  general,  and  the  facts  given  will  apply  to  all  kinds  of 
steel,  exceptions  being  pointed  out  when  they  occur. 

The  first  general  division  of  steel  is  cemented  or  con- 
verted steel,  known  to  the  trade  as  blister-steel,  Gertnan, 
shear,  and  double-shear  steel. 

This  is  probably  the  oldest  of  all  known  kinds  of  steel, 
as  there  is  no  record  of  the  beginning  of  its  manufacture. 
This  steel  is  based  upon  the  fact  that  when  iron  not  satu- 
rated with  carbon  is  packed  in  carbon,  with  all  air  excluded, 


2  STEEL: 

and  subjected  to  a  high  temperature,— any  temperature 
above  a  low  red  heat,— carbon  will  be  absorbed  by  the  iron 
converting  it  into  steel,  the  steel  being  harder  or  milder, 
containing  more  or  less  carbon,  determined  by  the  tempera- 
ture and  the  time  of  contact. 

Experience  and  careful  experiment  have  shown  that,  at 
a  bright  orange  heat  carbon  will  penetrate  iron  at  the  rate 
of  about  one  eif/JilJt  of  an  inch  it/  twenty-four  hours.  This 
applies  to  complete  saturation,  above  100  carbon;  liquid 
steel  will  absorb  carbon  with  great  rapidity,  becoming 
saturated  in  a  few  minutes,  if  enough  carbon  be  added  to 
cause  saturation. 

MANUFACTURE    OF    BLISTER-STEEL. 

Bars  of  wrought  iron  are  packed  in  layers,  each  bar  sur- 
rounded by  charcoal,  and  the  whole  hermetically  sealed  in  a 
fire-brick  vessel  luted  on  top  with  clay;  heat  is  then  applied 
until  the  whole  is  brought  up  to  a  bright  orange  color,  and 
this  heat  is  maintained  as  evenly  as  possible  until  the  whole 
mass  of  iron  is  penetrated  by  carbon;  usually  bars  about 
three  quarters  of  an  inch  thick  are  used,  and  the  heat  is 
required  to  be  maintained  for  three  days,  the  carbon, 
entering  from  both  sides,  requiring,  three  days  to  travel 
three  eighths  of  an  inch  to  the  centre  of  the  bar.  If  the 
furnace  be  running  hot,  the  conversion  may  be  complete 
in  two  days,  or  less.  The  furnace  is  then  cooled  and  the  bars 
are  removed;  they  are  found  to  be  covered  with  numerous 
blisters,  giving  the  steel  its  name. 

The  bars  of  tough  wrought  iron  are  found  to  be  con- 
verted into  highly  crystalline,  brittle  steel.  When  blister- 
steel  is  heated  and  rolled  directly  into  finished  bars,  it  is 
known  commercially  as 


A  MANUAL   FOR  STEEL-USERS.  3 

GERMAN  STEEL. 

When  blister-steel  is  heated  to  a  high  heat,  welded 
under  a  hammer,  and  then  finished  under  a  hammer  either 
nt  the  same  heat  or  after  a  slight  re-heating,  it  is  known  as 

SHEAR-STEEL,  OR  SINGLE-SHEAR. 

When  single-shear  steel  is  broken  into  shorter  lengths, 
piled,  heated  to  a  welding  heat  and  hammered,  and  then 
hammered  to  a  finish  either  at  that  heat  or  after  %  slight 
re-heating,  it  is  known  as 

DOUBLE-SHEAR  STEEL. 

Seebohm  gives  another  definition  of  single-shear,  and 
double-shear;  probably  both  are  correct,  being  different 
shop  designations. 

Until  within  the  last  century  the  above  steels  were  the 
only  kinds  known  in  commerce.  There  was  a  little  steel 
made  in  India  by  a  melting  process,  known  as  Wootz.  It 
amounted  to  nothing  in  the  commerce  of  the  world,  and  is 
mentioned  because  it  is  the  oldest  of  known  melting 
processes. 

Although  converted  steel  is  so  old,  and  so  few  years  ago 
was  the  only  available  kind  of  steel  in  the  world,  nothing 
more  need  be  said  of  it  here,  as  it  has  been  almost  super- 
seded by  cast  steel,  superior  in  quality  and  cheaper  in  cost, 
except  in  crucible-steel. 

Inquiring  readers  will  find  in  Percy,  and  many  other 
works,  such  full  and  detailed  accounts  of  the  manufacture 
of  these  steels  that  it  would  be  a  waste  of  space  and  time 
to  reprint  them  here,  as  they  are  of  no  more  commercial 
importance. 


4  STEKL: 

In  the  last  century  Daniel  Huntsman,  of  England,  a 
maker  of  clocks,  found  great  difficulty  in  getting  reliable, 
durable,  and  uniform  springs  to  run  his  clocks.  It  oc- 
curred to  him  that  he  might  produce  a  better  and  more  uni- 
form article  by  fusing  blister-steel  in  a  crucible.  He  tried 
the  experiment,  and  after  the  nsnal  troubles  of  a  pioneer- 
he  succeeded,  and  produced  the  article  he  required.  This 
founded  and  established  the  great  Crucible-cast-steel  in- 
dustry, whose  benefits  to  the  arts  are  almost  incalculable; 
and  none  of  the  great  inventions  of  the  latter  half  of  this 
nineteenth  century  have  produced  anything  equal  in  quality 
to  the  finer  grades  of  crucible-steel. 

CRUCIBLE-CAST   STEEL 

is  the  second  of  the  four  general  kinds  of  steel  mentioned 
in  the  beginning  of  this  chapter. 

Although  Huntsman  succeeded  so  well  that  he  is  clearly 
entitled  to  the  credit  of  having  invented  the  crucible  proc- 
ess, he  met  with  many  difficulties,  from  porosity  of  his 
ingots  mainly;  this  trouble  was  corrected  largely  by  Heath 
by  the  use  of  black  oxide  of  manganese.  Heath  attempted 
to  keep  his  process  secret,  but  it  was  stolen  from  him,  and 
he  spent  the  rest  of  a  troubled  life  in  trying  to  get  some 
compensation  from  the  pilferers  of  his  process.  An  inter- 
esting and  pathetic  account  of  his  troubles  will  be  found 
in  Percy. 

Heath's  invention  was  not  complete,  and  it  was  finished 
by  the  elder  Mushet,  who  introduced  in  addition  to  the 
oxide  of  manganese  a  small  quantity  of  ferro-manganese,  an 
alloy  of  iron  and  manganese;  and  it  was  now  possible,  with 
care  and  skill,  to  make  a  quality  of  steel  which  for  uni- 


A   MANUAL  FOR  STEEL-USERS.  5 

formity,  strength,  and  general  utility  has  never  been 
equalled. 

Crucible-steel  was  produced  then  by  charging  into  a 
crucible  broken  blister-steel,  a  small  quantity  of  oxide  of 
manganese,  and  of  ferro-manganese,  or  Spiegel-eisen,  cover- 
ing the  crucible  with  a  cap,  and  melting  the  contents  in  a 
coke-furnace,  a  simple  furnace  where  the  crucible  was 
placed  on  a  stand  of  refractory  material,  surrounded  by 
coke,  and  fired  until  melted  thoroughly. 

The  first  crucibles  used,  and  those  still  used  largely  in 
Sheffield,  were  made  of  fire-clay ;  a  better,  larger,  and  more 
durable  crucible,  used  in  the  United  States  exclusively, 
and  in  Europe  to  some  extent,  is  made  of  plumbago, 
cemented  by  enough  of  fire-clay  to  make  it  strong  and 
tough.  As  the  demands  for  steel  increased  and  varied  it 
was  found  that  the  carbon  could  be  varied  by  mixing 
wrought  iron  and  blister-bar,  and  so  a  great  variety  of 
tempers  was  produced,  from  steel  containing  not  more  than 
0.10#  of  carbon  up  to  steel  containing  1.50#  to  2#  of 
carbon,  and  even  higher  in  special  cases. 

It  \vas  soon  found  that  the  amount  of  carbon  in  steel 
could  be  determined  by  examining  the  fractures  of  cold 
ingots;  the  fracture  due  to  a  certain  quantity  of  carbon  is 
so  distinct  and  so  unchanging  for  that  quantity  that,  once 
known,  it  cannot  be  mistaken  for  any  other.  The  ingot  is 
so  sensitive  to  the  quantity  of  carbon  present  that  differ- 
ences of  .05$  may  be  observed,  and  in  everyday  practice 
the  skilled  inspector  will  select  fifteen  different  tempers  of 
ingots  in  steels  ranging  from  about  50  carbon  to  150  car- 
bon, the  mean  difference  in  carbon  from  one  temper  to 
another  being  only  .07#.  And  this  is  no  guess-work ;— no 
chemical  color  determination  will  approach  it  in  accuracy, 


6  STEEL: 

and  such  work  can  only  be  checked  by  careful  analysis  by 
combustion. 

This  is  the  steel-maker's  greatest  stronghold,  as  it  is  pos- 
sible by  this  means  for  a  careful,  skilful  man  to  furnish  to 
a  consumer,  year  after  year,  hundreds  or  thousands  of  tons 
of  steel,  not  one  piece  of  which  shall  vary  in  carbon  more 
than  .05$  above  or  below  the  mean  for  that  temper. 

The  word  "  temper  "  used  here  refers  to  the  quantity  of 
carbon  contained  in  the  steel,  it  is  the  steel-maker's  word; 
the  question,  What  temper  is  it?  answered,  No.  3,  No.  G, 
or  any  other  designation,  means  a  fixed,  definite  quantity 
of  carbon. 

When  a  steel-user  hardens  a  piece  of  steel,  and  then  lets 
down  the  temper  by  gentle  heating,  and  he  is  asked,  What 
temper  is  it  ?  he  will  answer  straw,  light  brown,  brown*, 
pigeon-wing,  light  blue,  or  blue,  as  the  case  may  be,  and  he 
means  a  fixed,  definite  degree  of  softening  of  the  hardened 
steel. 

It  is  an  unfortunate  multiple  meaning  of  a  very  com- 
mon word,  yet  the  uses  have  become  so  fixed  that  it  seems 
to  be  impossible  to  change  them,  although  they  sometimes 
cause  serious  confusion. 

The  quantity  of  carbon  contained  in  steel,  and  indeed  of 
all  ingredients,  as  a  rule,  is  designated  in  one  hundredths 
of  one  per  cent;  thus  ten  (.10)  carbon  means  ten  one  hun- 
dredths of  one  per  cent;  nineteen  (.19)  carbon  means  nine- 
teen one  hundredths  of  one  per  cent;  one  hundred  and 
thirty-five  (1.35)  carbon  means  one  hundred  and  thirty- 
five  one  hundredths  of  one  per  cent,  and  so  on.  So  also 
for  contents  of  silicon,  sulphur,  phosphorus,  manganese 
and  other  usual  ingredients. 

This  enumeration  will  be  used  in  this  work,  and  care 


A   MANUAL  FOR  STEEL-USERS.  7 

will  be  taken  to  use  the  word  "  temper"  in  such  a  way  as 
not  to  cause  confusion. 

It  has  been  stated  that  crucible-cast  steel  is  made  from 
tcu  carbon  up  to  two  hundred  carbon,  and  that  its  content 
of  carbon  can  be  determined  by  the  eye,  from  fifty  carbon 
upwards,  by  examining  the  fracture  of  the  ingots.  The 
limitation  from  fifty  carbon  upwards  is  not  intended  to 
mean  that  ingots  containing  less  than  fifty  carbon  have  no 
distinctive  structures  due  to  the  quantity  of  carbon;  they 
have  such  distinctive  structures,  and  the  difficulty  in  ob- 
serving them  is  merely  physical. 

Ingots  containing  fifty  carbon  are  so  tough  that  they 
can  only  be  fractured  by  being  nicked  with  a  set  deeply, 
and  then  broken  off;  below  about  fifty  carbon  the  ingots 
are  so  tough  that  it  is  almost  impossible  to  break  open  a 
large  enough  fracture  to  enable  the  inspector  to  determine 
accurately  the  quantity  of  carbon  present;  therefore  it  is 
usual  in  these  milder  steels,  when  accuracy  is  required, 
to  resort  to  quick  color  analyses  to  determine  the  quan- 
tity of  carbon  present.  Color  analyses  below  fifty  carbon 
may  be  fairly  accurate,  above  fifty  carbon  they  are  worth- 
less. 

As  the  properties  and  reliability  of  crucible-steel  be- 
came better  known  the  demand  increased,  and  the  re- 
quirements varied  and  were  met  by  skilful  manufacturers, 
until,  by  the  year  I860,  ingots  were  produced  weighing 
many  tons  by  pouring  the  contents  of  many  crucibles  into 
one  mould ;  in  this  way  the  more  urgent  demands  were 
met,  but  the  material  was  very  expensive  and  the  risks  in 
manufacturing  were  great.  About  this  time,  stimulated 
by  the  desire  of  enlightened  governments  to  increase  their 
powers  of  destruction  in  war  by  the  use  of  heavy  guns  of 


g  STEEL: 

greater  power  than  could  be  obtained  by  the  use  of  cast 
iron,  and  for  heavier  ship-armor  to  be  used  in  defence, 
Mr.  Bessemer,  of  England,  now  Sir  Henry  Bessemer,  rea- 
soned that  if  melted  cast  iron  was  reduced  to  wrought 
iron  by  puddling,  or  boiling,  by  the  mere  oxidation,  or 
burning  out,  of  the  excess  of  carbon  and  silicon  from 
the  cast  iron,  that  the  same  cast  iron  might  be  reduced  to 
steel  in  large  masses  by  blowing  air  through  a  molten  mass 
in  a  close  vessel,  retaining  enough  heat  to  keep  the  mass 
molten  so  that  the  resulting  steel  could  be  poured  into 
ingots  as  large  as  might  be  desired.  At  about  the  same 
time,  or  a  little  earlier,  Mr.  Kelly,  of  the  United  States, 
devised  and  patented  the  same  method.  Both  of  these 
gentlemen  demonstrated  the  potencies  of  their  invention, 
and  neither  brought  it  to  a  successful  issue. 

To  persistent  and  intelligent  iron-masters  of  Sweden 
must  be  given  the  credit  of  bringing  the  process  of  Besse- 
mer to  a  commercial  success,  and  so  they  gave  to  the 
world  pneumatic  or  Bessemer  steel,  the  latter  name  hold- 
ing, properly,  as  a  just  tribute  to  the  inventor,  and  this 
inaugurated  the  third  general  division : 


BESSEMER   STEEL. 

Bessemer  steel  is  made  by  pouring  into  a  bottle-shaped 
vessel  lined  with  refractory  material  a  mass  of  molten 
cast  iron,  and  then  blowing  air  through  the  iron  until  the 
carbon  and  silicon  are  burned  out.  The  gases  and  flame 
resulting  escape  from  the  mouth  of  the  vessel. 

The  combustion  of  carbon  and  silicon  produce  a  tem- 
perature sufficient  to  keep  the  mass  thoroughly  melted,  so 


A    MANUAL    FOR   STEEL-USERS.  9 

that  the  steel  may  be  poured  into  moulds  making  ingots  of 
any  desired  size. 

In  the  beginning,  and  for  many  years,  the  lining  of  the 
vessel  was  of  silicious  or  acid  material,  and  it  was  found 
that  all  of  the  phosphorus  and  sulphur  contained  in  the 
cast  iron  remained  in  the  resulting  steel,  so  that  it  was 
necessary  to  have  no  more  of  these  elements  in  the  cast 
iron  than  was  allowable  in  the  steel.  The  higher  limit  for 
phosphorus  was  fixed  at  ten  points  (.10#),  and  that  is  the 
recognized  limit  the  world  over.  When  Bessemer  pig  is 
quoted,  or  sold  and  bought,  it  means  always  a  cast  iron 
containing  not  more  than  ten  phosphorus. 

In  regard  to  sulphur,  it  was  found  that  if  too  much 
were  present  the  material  would  be  red-short,  so  that  it 
could  not  be  worked  conveniently  in  the  rolls  or  under  the 
hammer,  and  that  when  the  amount  of  sulphur  present 
was  not  enough  to  produce  red-shortness  it  was  not  suffi- 
cient to  hurt  the  steel. 

As  red-short  material  is  costly  and  troublesome  to  the 
manufacturer,  it  was  not  found  necessary  to  fix  any  limit 
for  sulphur,  because  the  makers  could  be  depended  upon 
to  keep  it  within  working  limits. 

Later  investigations  prove  this  to  be  a  fallacy,  as  much 
as  ten  or  even  more  sulphur  has  been  found  in  broken 
rails  and  shafts,  the  steel  having  made  workable  by  a  per- 
centage of  manganese.  (See  the  results  of  Andrews's  in- 
vestigation given  in  Chap.  X.) 

During  the  operation  of  blowing  Bessemer  steel  the 
flame  issuing  from  the  vessel  is  indicative  of  the  elimina- 
tion of  the  elements,  and  it  is  found  that  while  the  com- 
bustion is  partially  simultaneous  the  silicon  is  all  removed 
before  the  carbon,  and  the  characteristic  white  flume 


10  STEEL: 

towards  the  end  of  the  blow  is  known  as  the  carbon  flame; 
when  the  carbon  is  burned  out,  this  flame  drops  suddenly 
and  the  operator  knows  that  the  blow  is  completed.  Any 
subsequent  blowing  would  result  in  burning  iron  only. 
During  the  blow  the  steel  is  charged  heavily  with  oxygen, 
and  if  this  were  left  in  the  steel  it  would  be  rotten,  red- 
short,  and  worthless.  This  oxygen  is  removed  largely  by 
the  addition  of  a  predetermined  quantity  of  ferro-man- 
ganese,  usually  melted  previously  and  then  poured  into  the 
steel. 

The  manganese  takes  up  the  greater  part  of  the  oxygen, 
leaving  the  steel  free  from  red  shortness  and  easily 
worked. 

The  fact  that  the  phosphorus  of  the  iron  remained  in 
the  steel  notwithstanding  the  active  combustion  and 
high  temperature  led  to  the  dictum  that  at  high  temper- 
atures phosphorus  could  not  be  eliminated  from  iron. 
This  conclusion  was  credited  because  in  some  of  the  so- 
called  direct  processes  of  making  iron  where  the  tempera- 
ture was  never  high  enough  to  melt  steel  all,  or  nearly  all, 
of  the  phosphorus  was  removed  from  the  iron. 

For  many  years  steel-makers  the  world  over  worked 
upon  this  basis,  and  devoted  themselves  to  procuring  for 
their  work  iron  containing  not  more  than  ten  (.10)  phos- 
phorus, now  universally  known  and  quoted  as  Bessemer 
iron. 

Two  young  English  chemists,  Sidney  Gilchrist  Thomas 
and  Percy  C.  Gilchrist,  being  careful  thinkers,  concluded 
that  the  question  was  one  of  chemistry  and  not  one  of 
temperature;  accordingly  they  set  to  work  to  obtain  a  basic 
lining  for  the  vessel  and  to  produce  a  basic  slag  from  the 
blow  which  should  retain  in  it  the  phosphorus  of  the 


A   MANUAL   FOR  STEEL-USERS.  11 

iron.  After  the  usual  routine  of  experiment,  and  against  the 
doublings  of  the  experienced,  they  succeeded,  and  produced 
a  steel  practically  free  from  phosphorus.  For  the  practi- 
cal working  of  their  process  it  was  found  better,  or  neces- 
sary, to  use  iron  low  in  silicon  and  high  in  phosphorus, 
using  the  phosphorus  as  a  fuel  to  produce  the  high  tem- 
perature that  is  necessary  instead  of  the  silicon  of  the 
acid  process.  In  the  acid  process  it  is  found  necessary  to 
have  high  silicon  — two  per  cent  or  more — to  produce  the 
temperature  necessary  to  keep  the  steel  liquid;  in  the 
Thomas-Gilchrist  process  phosphorus  takes  the  place  of 
silicon  for  this  purpose. 

In  this  way  the  basic  Bessemer  process  was  worked  out 
and  became  prominent. 

The  basic  Bessemer  process  is  of  great  value  to  England 
and  to  the  continent  of  Europe  by  enabling  manufacturers 
to  use  their  native  ores,  which  are  usually  too  high  in  phos- 
phorus for  the  acid  process,  so  that  before  this  invention 
nearly  all  of  the  ores  for  making  Bessemer  steel  were  im- 
ported from  Sweden,  Spain,  and  Africa. 

The  basic  process  has  found  little  development  in  the 
United  States,  because  the  great  abundance  of  pure  ore 
keeps  the  acid  process  the  cheaper,  except  in  one  or  two 
special  localities.  Where  the  basic  process  is  profitable  in 
the  United  States,  it  is  worked  successfully. 

At  about  the  time  that  Bessemer  made  his  invention 
William  Siemens,  afterward  Sir  William,  invented  the  well- 
known  regenerative  gas-furnace.  A  Frenchman  named 
Martin  utilized  this  furnace  to  melt  steel  in  bulk  in  the 
hearth  of  the  furnace,  developing  what  was  known  for 
some  years  as  Siemens-Martin  steel,  or  open-hearth  steel; 
the  latter  name  has  prevailed,  and  open-hearth  steel  is 


12  STEEL: 

the  fourth  of  the  general  kinds  of  steel  mentioned  in  the 
beginning  of  this  chapter. 

At  first  open- hearth  steel  was  made  upon  a  specially 
prepared  sand  bottom,  by  first  melting  a  bath  of  cast  iron 
and  then  adding  wrought  iron  to  the  bath  until  by  the  ad- 
ditions of  wrought  iron  and  the  action  of  the  flame  the 
carbon  and  silicon  of  the  cast  iron  were  reduced  until  the 
whole  became  a  mass  of  molten  steel.  Sometimes  iron  ore 
is  used  instead  of  wrought  iron  as  the  reducing  agent;  this 
is  called  the  pig  and  ore  process.  Now  in  general  prac- 
tice wrought  iron,  steel  scrap,  and  iron  ore  are  used,  some- 
times alone  and  sometimes  together,  as  economy  or  special 
requirements  make  it  convenient. 

It  was  found  as  in  the  Bessemer,  so  in  the  open -hearth, 
the  sulphur  and  the  phosphorus  of  the  charge  remained 
in  the  steel,  making  it  necessary  to  see  that  in  the  charge 
"there  was  no  more  of  these  elements  than  the  steel  would 
bear. 

This  is  known  now  as  the  acid  open-hearth  process. 

After  the  success  of  the  basic  Bessemer  process  was  as- 
sured the  same  principle  was  tried  in  the  open-hearth; 
a  basic  bottom  of  dolomite  or  of  magnesite  was  substituted 
for  the  acid  sand  bottom,  and  care  was  taken  to  secure  a 
basic  slag  in  the  bath. 

Success  was  greater  than  in  the  Bessemer;  phosphorus 
was  eliminated  and  a  better  article  in  every  way  was  made 
by  this  process,  now  used  extensively  over  the  whole  civil- 
ized world. 

This  is  the  basic  open-hearth  process. 

Neither  the  basic  Bessemer  process  nor  the  basic  open- 
hearth  removed  sulphur,  so  that  this  element  must  still  be 


A  MANUAL  FOR  STEEL-USERS.  13 

kept  low  in  the  original  charge,  until  some  way  shall  be 
found  for  its  sure  and  economical  elimination. 

The  four  general  divisions,  then,  axe: 

Converted  or  Cemented  Steel 

Crucible-cast  Steel. 


Bessemer    j      *     i  Cast  Steel 
(  Basic  ) 

Open-hearth    \  ^°ld  i  Cast  Steel. 
(  Basic  ) 


Little  or  nothing  more  will  be  said  of  the  first  kind,  as  it 
has  been  so  thoroughly  superseded  by  the  cast  steels. 
After  a  statement  of  the  most  patent  applications  and  uses 
of  the  different  cast  steels  the  discussions  which  follow 
will  apply  to  all,  because  practically  they  are  all  governed 
by  the  same  general  laws. 


14  STEEL : 


II. 

APPLICATIONS  AND  USES  OF  THE  DIFFER- 
ENT  KINDS  OF  STEEL. 

WHERE  exact  uniformity  of  composition  is  not  a  neces- 
sity, and  where  welding  is  required,  cemented  or  converted 
steel  may  be  preferred  to  cast  steel,  because  the  converted 
bar  retains  the  occluded  layers  of  slag  which  give  to 
wrought  iron  its  peculiar  welding  properties,  and  for  this 
reason  blister-  or  shear-steel  may  be  welded  more  easily  and 
surely  than  cast  steel.  For  tires,  composite  dies,  and  many 
compound  articles  this  steel  will  do  very  well,  and  it  may 
be  worked  with  good  results  by  almost  any  smith  of  ordi- 
nary skill;  however,  owing  to  the  more  uniform  structure 
and  the  greater  durability  of  the  cast  steels,  they  have,  even 
for  these  purposes,  almost  entirely  displaced  the  more 
easily  worked,  but  less  durable,  cemented  steels. 

CKUCIBLE-CAST   STEEL. 

For  all  purposes  crucible-steel  has  proved  to  be  superior 
to  all  others;  it  is  well  known  to  all  experienced  and  ob- 
serving workers  in  steel  that,  given  an  equal  composition, 
crucible  is  stronger  and  more  reliable  in  every  way  than 
any  of  the  other  kinds  of  steel. 

This  may  read  like  a  mere  dictum,  and  it  might  be  asked 
properly,  What  are  the  proofs  ? 

The  proofs  are  wanting  for  two  reasons:  first,  because 


A  MANUAL  FOR  STEEL-USERS.  15 

crucible-steel  is  so  expensive  that  except  for  gun  parts, 
armor,  and  such  uses  where  expense  could  be  ignored,  cru- 
cible-steel never  came  into  extensive  use  for  structural 
purposes;  second,  that  while  thousands  upon  thousands  of 
tests  of  the  cheaper  steels  are  recorded  and  available  to 
engineers  very  few  of  such  tests  have  been  made  on  cru- 
cible-steel, simply  because  it  has  not  been  used  for  struc- 
tural purposes. 

On  the  other  hand,  intelligent  makers  of  crucible-steel 
have  for  self-preservation  made  careful  study  of  the  rela- 
tive properties  of  the  different  steels  in  order  that  they 
might  know  what  to  expect  from  the  cheaper  processes. 
In  this  way  they  have  surrendered  boiler-steel,  spring-steel, 
machinery-steel,  battering-tool  steel,  cheap  die-steel,  and 
many  smaller  applications;  not  because  they  could  not  pro- 
duce a  better  article,  but  because  the  cheaper  steels  met  the 
requirements  of  consumers  satisfactorily,  and  therefore  they 
could  not  be  expected  to  pay  a  higher  price  for  an  article 
whose  superiority  was  not  a  necessity  in  their  requirements. 

Still  this  stated  superiority  is  proven  best  by  the  fact 
that  many  careful  consumers  who  have  special  reasons  for 
studying  durability  as  against  first  cost  adhere  to  the 
higher  priced  crucible-steel  for  such  uses  as,  for  instance, 
parts  of  mining-  and  quarrying-drills,  high-speed  spindles, 
in  cotton-mills,  and  in  expensive  lathes  and  machines  of 
that  kind. 

This  sort  of  testimony  should  be  more  conclusive  than 
that  of  interested  steel-makers,  because  these  men  pay 
their  own  money  for  the  higher  priced  material,  and  be- 
cause men  who  are  most  careful  of  the  quality  of  their 
produce  and  of  their  reputation  are  the  most  clear- 
headed and  most  sensible  men  of  their  class;  they  have 


16  STEEL: 

the  best  business  and  the  greatest  success.  Such  men  are 
not  fools;  they  may  be  depended  upon  to  try  everything  of 
promise  with  the  greatest  care,  and  to  use  only  that  thing 
which  pays  them  best.  In  fact  such  men  do  use  the 
cheaper  steels  freely  wherever  they  can  do  so  safely. 

A  good  car-spring,  carriage-spring,  or  wagon-spring  is 
made  from  Bessemer  or  open-hearth  steel,  a  spring  that 
will  wear  out  the  car  or  carriage;  it  would  be  stupid  then 
to  buy  more  expensive  steel  for  such  purposes,  for  even  if 
crucible-steel  would  wear  out  two  cars  or  two  wagons  the 
owner  never  expects  to  take  the  springs  out  of  an  old 
wagon  to  put  them  under  a  new  one. 

On  the  other  hand,  the  watch-spring  maker  or  the  clock- 
spring  maker  will  find  a  great  advantage  in  using  the 
very  best  crucible-steel  that  can  be  made. 

A  sledge,  a  maul,  or  a  hammer  can  be  made  of  such  ex- 
cellent quality  from  properly  selected  Bessemer  or  open- 
hearth  steel  that  it  would  be  foolish  for  makers  of  such 
tools  to  continue  to  buy  crucible-steel,  even  though  they 
knew  it  to  be  superior,  for  lower  first  cost  in  such  cases 
outweighs  superiority  that  cannot  be  shown  for  a  number 
of  years. 

Locomotive-boilers,  crank-pins,  slide-rods,  connecting- 
rods,  and  springs  can  be  made  of  such  good  quality  of 
Bessemer  or  open-hearth  steel  that,  like  the  "  one-horse 
shay,"  the  whole  machine  will  wear  out  at  the  same  time 
practically,  and  that  a  good  long  time;  there  would  be  no 
reason  in  this  case  for  using  crucible-steel  for  one  or  more 
of  these  parts,  although  twenty-five  years  ago  it  was  by 
means  of  crucible-steel  that  engineers  learned  to  use  steel 
for  these  purposes. 

A  good  cam  for  an  ordinary  machine,  such  as  a  shear  or 


A  MANUAL  FOR  STEEL-USERS.  17 

punch,  may  be  made  of  Bessc'iucr  or  open-hearth  steel 
where  greater  strength  and  endurance  are  required  than 
can  be  had  in  cast  iron;  on  the  other  hand,  makers  of  cams 
for  delicately  adjusted  high-speed  machines  where  intricacy 
and  accuracy  are  necessary  will  touch  nothing  but  the 
very  best  crucible-steel  of  fine-tool  quality  for  their  work. 
It  is  of  no  use  to  suggest  the  greater  cheapness  of  the 
other  steels;  they  have  tried  them  thoroughly,  and  they 
know  that  in  their  case  the  highest  priced  is  the  cheapest. 
This  superiority  of  crucible-steel  has  been  doubted,  be- 
cause the  claim  appeared  to  rest  solely  upon  the  statements 
of  steel-makers,  and  not  to  have  any  scientific  basis;  there 
is,  however,  a  scientific  basis  for  the  fact.  Given  three 
samples  of  steel  of  say  the  following  composition : 

Crucible.    Open-hearth.     Bessemer. 

Carbon 1.00  1.00  1.00 

Silicon 10  .10  .10 

Phosphorus 05  .05  .05 

Sulphur 02  .02  .02 

Copper,  arsenic,  etc traces 

Why  should  there  be  any  difference  in  the  strength  of 
the  three  ?  In  mere  tensile  strength  in  an  untempered 
bar  the  difference  might  not  be  very  great,  although  all 
experienced  persons  would  expect  the  crucible  to  show  the 
highest;  but  it  is  not  necessary  to  make  the  claim,  because 
we  have  not  enough  tests  of  crucible-steel  to  enable  us  to 
establish  a  mean,  and  one  or  two  tests  are  insufficient  to 
establish  a  rule  in  any  case. 

There  have  been  made,  however,  hundreds  of  tests  of 
hardened  and  tempered  samples  by  the  most  expert  per- 
sons, with  one  invariable  result:  the  crucible-steel  is  in- 


18  STEEL: 

comparably  finer  and  stronger  than  the  others,  and  the 
open-hearth  is  almost  invariably  stronger  and  finer  than 
the  Bessemer. 

Unfortunately  for  the  argument  these  tests  cannot  be 
recorded  so  as  to  be  intelligible  to  the  non-expert,  because 
we  cannot  tabulate  the  result  of  the  touch  of  the  expert 
hand  or  the  observation  of  the  experienced  eye. 

For  a  time  it  was  popular  to  call  these  differences 
mysteries,  and  so  let  them  pass;  this,  however,  was  not 
satisfactory,  and  the  question  was  studied  carefully  for  the 
physical  reasons  which  must  exist. 

Much  thought  led  to  the  conclusion  that  the  reason  lay 
with  the  three  elements  oxygen,  nitrogen,  and  hydrogen; 
they  are  known  to  exist  in  greater  or  less  quantity  in  all 
iron  and  steel. 

It  is  known  that  the  presence  of  oxygen  beyond  certain 
small  limits  produces  red-shortness  and  general  weakness; 
it  is  probably  a  much  more  hurtful  element  than  phospho- 
rus or  sulphur,  but  no  quantitative  method  for  its  deter- 
mination has  been  worked  ont;  there  is  an  effort  now 
being  made  to  develop  a  simple  and  expeditious  oxygen 
determination,  and  it  is  to  be  hoped  that  it  will  be  success- 
ful. 

In  the  crucible  no  more  oxygen,  hydrogen,  or  nitrogen 
can  get  into  the  steel  than  is  contained  in  the  material 
charged  and  in  the  atmosphere  of  the  crucible,  or  than 
may  penetrate  the  walls  of  the  crucible  during  melting. 
In  the  open  hearth  the  process  is  an  oxidizing  one,  and 
besides  the  charge  is  swept  continuously  by  hot  flames 
containing  all  of  these  elements. 

In  the  Bessemer  process  the  conditions  are  worse  still, 


A  MANUAL  FOR  STEEL-USERS.  19 

as  these  elements  are  all  blown  through  the  whole  mass  of 
the  steel. 

We  know  the  effect  of  oxygen  and  how  to  eliminate  it 
practically. 

Percy  gives  the  effects  of  nitrogen  as  causing  hardness 
and  extreme  brittleness,  and  giving  to  iron  or  steel  a  brassy 
lustre.  Such  a  brassy  lustre  may  be  seen  frequently  in 
open-hearth  or  Bessemer  steel,  and  occasionally  in  crucible- 
steel.  When  seen  in  crucible-steel  it  is  known  to  be  due 
to  the  fact  that  the  cap  of  the  crucible  became  displaced, 
exposing  the  contents  to  the  direct  action  of  the  flame. 
Of  the  effect  of  hydrogen  we  know  less;  there  is  no  reason 
apparent  why  it  may  not  be  as  potent  as  the  others. 

Ammonia  in  sufficient  quantity  to  be  detected  by  the 
nose  has  often  been  observed  in  open-hearth  and  Bessemer 
steel. 

To  settle  the  nitrogen  question  Prof.  John  W.  Lang- 
ley  developed  some  years  ago  a  very  delicate  and  accurate 
process  for  the  determination  of  nitrogen  even  in  minute 
quantities;  the  process  was  tedious  and  expensive,  so  that 
it  was  not  adapted  for  daily  use;  it  involved  the  careful 
elimination  of  nitrogen  from  all  of  the  reagents  to  be  used, 
requiring  several  days'  work,  in  each  case  to  prepare  for 
only  a  few  nitrogen  determinations. 

By  this  process  it  was  found,  in  every  one  of  many  trials, 
that  crucible-steel  contained  the  least  amount  of  nitrogen, 
open-hearth  steel  the  next  greater  quantity,  and  Bessemer 
steel  the  greatest  amount.  He  found  no  exceptions  to  this. 
For  many  years  great  efforts  had  been  made  both  in 
Europe  and  in  the  United  States  to  make  by  the  Bessemer 
or  the  open-hearth  process  a  cheap  melting-product  to 


20  STEEL : 

be  used  in  the  crucible  instead  of  the  expensive  irons  which 
so  far  have  proved  to  be  necessary  to  give  the  best  results. 

There  appeared  to  be  no  difficulty  in  making  a  material 
as  pure  chemically,  or  purer,  than  the  most  famous  irons 
in  the  world,  and  this  material  was  urged  upon  the  cruci- 
ble-steel makers.  Careful  tests  of  such  material  failed  to 
produce  the  required  article;  in  fact  it  was  demonstrated 
over  and  over  again  that  an  inferior  wrought  iron  would 
produce  a  stronger  steel  than  this  very  pure  steel  melting- 
material,  and  crucible-steel  makers  were  compelled  to 
adhere  to  the  more  costly  irons  to  produce  their  finer 
grades. 

Prof.  Langley  determined  the  nitrogen  in  a  given  quan- 
tity of  open-hearth  and  Bessemer  steel;  this  same  material 
was  then  melted  in  a  crucible,  and  it  was  found  that  the 
resulting  ingots  contained  nearly  as  much  nitrogen  as  the 
original  charge.  The  quantity  was  reduced  slightly;  still 
this  steel  contained  more  nitrogen  than  any  other  sample 
of  crucible-steel  that  he  had  tested.  The  physical  test  of 
this  trial  steel  showed  the  usual  weakness  of  the  Bessemer 
or  open-hearth  steel,  as  compared  to  crucible-steel. 

The  next  step  was  to  try  to  get  rid  of  nitrogen  by  the 
use  of  some  affinity,  as  oxygen  is  removed  by  manganese. 
Boron  and  titanium  seemed  to  be  the  most  feasible 
elements;  boron  appeared  to  offer  less  chance  of  success, 
and  titanium  was  selected.  A  ferro-titanium  containing 
six  per  cent  of  titanium  was  imported  from  Europe  at 
some  expense.  As  the  most  careful  and  exacting  analyses  of 
this  material  failed  to  reveal  a  trace  of  titanium,  it  was  not 
used. 

After  many  futile  efforts  Langley  succeeded,  by  means  of 


A    MANUAL   FOR   STEEL-USERS.  21 

electric  heat,  in  reducing  rutile  and  producing  a  small 
quantity  of  an  alloy  of  iron  and  titanium.  A  trial  of  this 
alloy,  although  not  conclusive,  led  to  the  belief  that  such  an 
alloy  could  be  used  successfully  to  eliminate  nitrogen;  but 
as  its  cost,  about  two  dollars  a  pound,  was  prohibitory  of 
any  commercial  use,  the  subject  was  not  pursued  farther. 

Although  we  know  these  elements  only  as  gases,  there  is 
no  reason  to  suppose  that  their  atoms  may  not  be  as  potent, 
when  added  to  steel,  us  atoms  of  carbon,  silicon,  phosphorus, 
or  any  other  substance. 

Such  are  the  facts  for  crucible-steel  as  far  as  they  are 
known;  it  is  vastly  more  expensive  than  any  other  kind  of 
steel,  yet  for  the  present  it  holds  its  own  unique  and  valua- 
ble place  in  the  arts. 

For  all  tools  requiring  a  fine  edge  for  cutting  purposes, 
such  as  lathe-tools,  drills,  taps,  reamers,  milling  cutters, 
axes,  razors,  pocket-knives,  needles,  graving- tools,  etc.;  for 
fine  dies  where  sharp  outline  and  great  endurance  are 
required;  for  fine  springs  and  fine  machinery  parts  and 
fine  files  and  saws,  and  for  a  hundred  similar  uses,  crucible- 
cast  steel  still  stands  pre-eminent,  and  must  remain  so 
until  some  genius  shall  remove  from  the  cheaper  steels  the 
elements  that  unfit  them  for  these  purposes. 

As  stated  before,  crucible-steel  is  divided  into  fifteen  or 
more  different  tempers,  ranging  in  carbon  from  .50  to  1.50. 
Each  of  these  tempers  has  its  specific  uses,  and  a  few  will 
be  pointed  out  in  a  general  way. 

.50  to  .60  carbon  is  best  adapted  for  hot  work  and  for 
battering-tools. 

.60  to  .70  carbon  for  hot  work,  battering-tools,  and  tools  of 
dull  edge. 


o£  STEEL: 

.70  to  .80  carbon  for  battering-tools,  cold-sets,  and  some 
forms  of  reamers  and  taps. 

.80  to  .90  carbon  for  cold-sets,  hand -chisels,  drills,  taps, 
reamers,  and  dies. 

.90  to  1.00  carbon  for  chisels,  drills,  dies,  axes,  knives,  and 
many  similar  purposes. 

1.00  to  1.10  carbon  for  axes,  hatchets,  knives,  large  lathe- 
tools,  and  many  kinds  of  dies  and  drills  if  care  be  used  in 
tempering  them. 

1.10  to  1.50  carbon  for  lathe-tools,  grav ing-tools,  scribers, 
scrapers,  little  drills,  and  many  similar  purposes. 

The  best  all-around  tool-steel  is  found  between  .90  and 
1.10  carbon;  steel  that  can  be  adapted  safely  and  success- 
fully to  more  uses  than  any  other  temper. 

At  somewhere  from  .90  to  1.00  carbon,  iron  appears  to  be 
saturated  with  carbon,  giving  the  highest  efficiency  in  tools 
and  the  highest  results  in  the  testing-machine  except  for 
compressive  strains.  More  will  be  said  upon  this  point  in 
treating  of  the  carbon-line. 

Much  more  could  be  said  about  the  uses  for  the  different 
tempers  of  steel;  it  would  be  easy  to  write  out  in  great 
detail  the  exact  carbon  which  experience  has  shown  to  be 
best  adapted  to  any  one  of  hundreds  of  different  uses,  but 
it  would  only  be  confusing  and  misleading  to  a  great 
many  people. 

It  is  within  the  experience  of  every  steel-maker  that 
men  are  just  as  variable  as  steel,  and  the  successful  steel- 
maker must  familiarize  himself  with  the  personal  equations 
of  his  patrons.  One  man  on  the  sunny  side  of  a  street  may 
be  making  an  excellent  kind  of  tool  from  a  certain  grade 
and  temper  of  steel,  and  be  perfectly  happy  and  prosperous 
in  its  use.  His  competitor  on  the  shady  side  of  the  street 


A  MANUAL  FOR  STEEL-USERS.  23 

may  fail  in  trying  to  use  the  same  steel  for  the  same  pur- 
pose and  condemn  it  utterly. 

The  know  it  all  agent  will  condemn  the  latter  man  with 
an  intimation  that  his  ears  are  too  long,  and  so  lose  his 
trade.  The  tactful  agent  will  supply  him  with  steel  a 
temper  higher  or  a  temper  lower,  until  he  hits  upon  the 
right  one,  and  so  will  retain  both  men  on  his  list;  and 
both  men  will  turn  out  equally  good  products. 

Few  men  know  their  own  personal  equations,  and  the 
best  way  for  a  steel-user  to  do  is  to  tell  the  steel-maker 
what  he  wants  to  accomplish,  and  put  upon  him  the  re- 
sponsibility of  selecting  the  best  temper. 

It  costs  no  more  to  make  and  to  provide  one  temper 
than  another;  therefore  the  one  inducement  of  the  steel- 
maker is  to  give  his  patron  that  which  is  best  adapted  to 
his  use.  This  plan  puts  all  of  the  responsibility  upon  the 
steel-maker,  just  where  it  ought  to  be,  because  he  should 
know  more  about  the  adaptability  of  his  steel  than  any 
other  person. 

BESSEMER   STEEL. 

Bessemer  steel  is  probably  the  cheapest  of  all  grades  of 
steel;  that  is  to  say,  it  can  be  made  so  rapidly,  so  continu- 
ously, and  in  such  enormous  quantities  that  a  greater 
output  per  dollar  invested  can  be  made  than  by  either  of 
the  other  processes.  Again,  the  work  is  controlled  and 
operated  by  machinery  to  a  much  greater  extent  than  in 
the  other  processes ;  therefore  the  cost  of  labor  per  ton  of 
product  both  for  skilled  and  unskilled  labor  is  less  than  in 
the  crucible  or  the  open-hearth  method. 

This  being  the  case,  it  might  be  inferred  that  the  result 
would  be  the  eventual  driving  out  of  all  other  steels  by 
this,  the  cheapest.  This  would  be  the  inevitable  result 


24  STEEL: 

if  Bessemer  steel  were  as  well  adapted  to  all  purposes  as 
either  of  the  other  kinds  of  steel;  there  are  limitations 
which  prevent  this. 

The  source  of  heat  in  the  Bessemer  process  is  in  the 
combustion  of  the  elements  of  the  charge,  there  is  no  ex- 
traneous source  of  heat;  therefore,  if  the  heat  be  too  cold, 
there  is  no  way  to  remedy  it  unless  it  be  by  the  addition 
of  ferro-silicon  and  more  blowing;  if  it  be  too  hot,  it  may 
be  allowed  to  stand  a  few  minutes  to  cool.  Still  in  either 
case  the  remedy  is  somewhat  doubtful.  This  limitation 
must  not  be  taken  as  being  fatal  to  good  work,  for  in  skil- 
ful hands  such  cases  are  rare,  and  the  product  is  generally 
fully  up  to  the  standard  of  good  work. 

As  there  is  no  known  sure  way  of  stopping  the  blow  at 
a  given  point  in  the  operation  to  produce  a  steel  of  re- 
quired carbon,  it  is  usual  to  blow  clear  down,  that  is,  to 
burn  out  all  of  the  carbon  practically  and  then  to  re  car- 
bonize by  the  addition  of  spiegel-eisen  or  ferro-manganese. 
It  is  necessary,  also,  to  add  the  manganese  in  one  of  these 
forms  to  remove  the  oxygen  introduced  during  the  blow; 
this  must  be  done  quickly,  and  all  accomplished  before 
the  metal  becomes  too  cold  for  pouring  into  ingots. 

So  little  time  for  reactions  is  available  that  it  is  doubtful 
if  the  material  is  ever  quite  as  homogeneous  as  it  can  be 
made  by  either  of  the  other  processes. 

Notwithstanding  these  limitations,  which  are  not  men- 
tioned to  throw  doubt  upon  the  process,  but  merely  to  in- 
form readers  fully  so  as  to  enable  them  to  judge  rightly  as 
to  what  may  be  expected,  enormous  quantities  of  good, 
reliable  Bessemer  steel  are  made  to  meet  many  require- 
ments. 

For  good,  serviceable,  cheap  rails  Bessemer  steel  stands 


A   MANUAL   FOR   STEEL-USERS.  25 

pre-eminent,  and  if  it  found  no  other  use  it  would  be  diffi- 
cult to  overestimate  the  benefit  to  the  world  of  this  one 
great  success. 

Bessemer  steel  is  used  largely  for  a  great  number  of  pur- 
poses, Bessemer  billets  being  now  as  regular  an  article  of 
commerce  as  pig  iron. 

For  wire  for  all  ordinary  purposes;  for  skelp  to  be 
worked  into  butt-welded  and  lap-welded  tubing;  for  wire 
nails,  shafting,  machinery-steel,  tank-plates,  and  for  many 
other  uses,  Bessemer  steel  has  absorbed  the  markets  almost 
entirely. 

For  common  cutlery,  files,  shovels,  picks,  battering-tools, 
and  many  such  uses  it  contests  the  market  with  open- 
hearth  steel;  and  while  many  engineers  now  specify  that 
their  structural  shapes,  plates,  beams,  angles,  etc.,  must  be 
of  open-hearth  steel,  there  are  many  eminent  engineers 
who  see  no  need  for  this  discrimination,  they  being  satis- 
fied that  if  their  requirements  are  met  the  process  by 
which  they  are  met  is  a  matter  of  indifference. 

OPEX-UEARTU   STEEL. 

As  in  the  Bessemer  process,  so  in  the  open-hearth,  car- 
bon and  silicon  are  burned  out,  phosphorus  is  removed  on 
the  basic  hearth,  and  the  sulphur  of  the  charge  remains  in 
the  steel.  During  the  operation  oxygen  and  nitrogen  are 
absorbed  by  the  steel,  although  not  quite  so  largely  as  in 
the  Bessemer  process,  so  that  practically  the  chemical  limi- 
tations are  the  same  in  each. 

The  open-hearth  reductions  are  much  slower  than  in  the 
Bessemer,  each  heat  requiring  from  five  to  eight  hours  for 
its  completion;  the  furnace  must  be  operated  by  a  skilled 
man  of  good  judgment,  so  that  more  time  and  more  skilled 


26  STEEL: 

labor  per  ton  of  product  are  required  than  in  the  Bessemer, 
aud  the  making  of  an  equal  quality  as  cheaply  in  the  open- 
hearth  is  problematical.  The  open-hearth  has  extraneous 
sources  of  heat  at  the  command  and  under  the  control  of 
the  operator,  and  there  need  be  no  cold  heats,  and  no  too 
hot  heats. 

The  time  for  reactions  is  much  longer,  and  for  this 
reason  they  ought  to  be  more  complete,  and  they  are  so  in 
good  hands;  yet  it  is  a  fact  that,  as  the  operation  is  a  quiet 
one  compared  to  the  Bessemer,  and  not  nearly  so  powerful 
aud  energetic,  a  careless  or  unskilful  operator  may  pro- 
duce in  the  open  hearth  an  uneven  result  that  is  quite  as 
bad  as  anything  that  can  be  brought  out  of  a  Bessemer 
converter.  The  process  that  eliminates  the  human  factor 
has  not  yet  been  invented. 

For  line  boiler-plates,  armor-plates,  and  gun  parts  open- 
hearth  steel  has  won  its  place  as  completely  as  has  the 
crucible  for  fine-tool  steel  or  the  Bessemer  for  rails. 

For  all  intermediate  products  there  is  a  continued  race 
and  keen  competition,  so  that  it  is  impossible  to  draw  any 
hard  and  fast  line  between  the  products  of  the  three  proc- 
esses where  they  approach  each  other;  the  only  clear  dis- 
tinctions are  at  the  other  extremes. 

Owing  to  the  power  to  hold  and  manipulate  a  heat  in 
the  open-hearth  it  is  safe  to  say  that  it  is  superior  to  the 
Bessemer  in  the  manufacture  of  steel  castings;  and  owing 
to  its  much  greater  cheapness  it  is  difficult  for  the  crucible 
to  compete  with  it  at  all  in  this  branch  of  manufacture. 

In  conclusion  of  this  chapter  it  is  safe  to  say  that  in 
good  hands  these  processes  are  ail  good,  and  each  has  its 
own  special  function  to  perform. 


A  MANUAL  FOR  STEEL-USERS.  27 


IIL 

ALLOY  STEELS  AND  THEIR  USES. 

IN  addition  to  the  four  general  kinds  of  steel  treated  of 
in  the  last  chapter  there  are  a  number  of  steels  in  the 
market  which  contain  other  metals,  and  which  may  be 
termed  properly  alloy  steels,  to  distinguish  them  from 
carbon  steel,  or  the  regular  steels  of  world- wide  use  which 
depend  upon  the  quantity  of  carbon  present  for  their 
properties.  The  most  generally  known  of  the  alloy  steels 
is  the  so-called  Self-Hardening  steel. 

Self-hardening  steel  is  so  called  because  when  it  is 
heated  to  the  right  temperature, — about  a  medium  orange 
color, — and  is  then  allowed  to  cool  in  the  air,  it  becomes 
very  hard.  This  steel  is  so  easily  strained  that  it  is  im- 
possible, as  a  rule,  to  quench  it  in  water  without  cracking 
it.  It  may  be  quenched  in  a  blast  of  air  without  crack- 
ing, and  so  be  made  much  harder  than  if  it  be  allowed  to 
cool  more  slowly  in  a  quiet  atmosphere.  If  it  be  quenched 
in  oil  or  water,  it  will  become  excessively  hard,  much 
harder  than  when  quenched  in  air,  and  it  will  almost  in- 
variably be  cracked,  or  if  it  be  not  cracked  it  will  be  so 
excessively  brittle  as  to  be  of  little  use. 

Self-hardened  steel  is  so  hard  in  what  may  be  called  its 
natural  condition,  that  is,  in  ordinarv  bar;?,  that  it  cannot 
be  machined,  drilled,  planed,  or  turned  in  a  lathe. 

By  keeping  it  in  an  annealing-furnace  at  about  bright 


28  STEEL: 

orange  heat  for  about  twenty-four  to  thirty-six  hours,  and 
then  covering  it  with  hot  sand  or  ashes  in  the  furnace, 
and  allowing  about  the  same  time  for  it  to  cool,  it  may 
be  annealed  pretty  thoroughly  so  that  it  may  bo  machined 
readily. 

When  annealed  in  this  way  and  formed  into  cutters  of 
irregular  shape,  or  dies,  it  has  been  found  so  far  not  to  be 
economical  or  well  adapted  to  such  work,  so  that  up  to  the 
present  time  annealing  is  more  of  a  scientific  than  a  useful 
fact. 

Self-hardened  steel  has  the  useful  property  of  retaining 
its  hardness  when  heated  almost  to  redness;  therefore  it 
may  be  used  as  a  lathe  or  similar  cutter  upon  hard  work, 
such  as  cutting  cast  iron  and  other  metals,  at  a  much 
higher  speed  than  is  possible  with  ordinary  steel,  which 
would  be  softened  by  the  heat  generated  by  the  high  speed. 
This  property  makes  self-hardened  steel  very  useful  and 
economical  for  many  purposes. 

Self-hardened  steel  is  an  alloy  of  iron,  carbon,  tungsten, 
and  manganese,  and  some  brands  contain  chromium  in 
addition  to  these,  and  it  is  claimed,  and  probably  truly, 
that  the  chromium  improves  the  quality  of  the  steel. 

It  was  supposed  for  a  long  time  that  tungsten  was  the 
hardener  that  gave  to  self-hardened  steel  its  peculiar  prop- 
erties. By  means  of  an  open  hearth,  steel  was  produced 
containing  about  3$  tungsten  and  little  carbon  and  man- 
ganese. This  steel  worked  like  any  mild  steel,  except  that 
it  was  hot-short  and  difficult  to  forge.  It  was  not  hard 
and  had  no  hardening  properties:  that  is,  it  did  not  harden 
in  the  ordinary  sense  when  quenched  in  water.  The  addi- 
tion of  carbon  to  this  steel,  keeping  the  manganese  low, 
produced  a  steel  very  difficult  to  work,  which  would  harden 


A   MANUAL  FOR  STEEL-USERS.  29 

like  ordinary  steel  when  quenched,  and  which  had  no 
self-hardening  properties  whatever.  The  addition  of  2£# 
to  3#  of  manganese  to  this  steel  produced  self-hardening 
steel  having  the  usual  properties. 

Manganese,  then,  is  the  metal  that  gives  the  self-harden- 
ing property,  and  this  might  have  been  anticipated  by 
considering  the  properties  of  Had  field's  manganese  steel, 
which,  when  it  contains  above  ?#  manganese,  cannot  be 
annealed  so  that  it  can  be  machined  or  drawn  into  wire. 
From  this  it  might  be  inferred  that  tungsten  is  not  a  nee. 
essary  constituent  of  self-hardened  steel;  that  it  performs 
an  important  function  will  be  shown  presently.  Tests  of 
the  iron-tungsten  alloy  low  in  carbon  gave  only  a  small 
increase  in  strength  above  ordinary  low  cast  steel  contain- 
ing little  carbon;  it  was  difficult  and  troublesome  to  work, 
and  more  expensive  than  the  common  steels,  so  that  its 
production  presented  no  advantages.  When  carbonized,  it 
was  fine-grained  and  could  be  made  exceedingly  hard;  it 
was  brittle,  and  compared  to  very  ordinary  cast  steel  com- 
paratively worthless. 

In  self-hardened  steel  tungsten  is  the  mordant  that 
holds  the  carbon  in  solution  and  enables  the  steel  to  retain 
its  hardness  at  comparatively  high  temperatures.  That  it 
does  hold  the  carbon  in  solution  may  be  proved  in  a  mo- 
ment by  a  beautiful  test,  first  observed  by  Prof.  John  W. 
Langley. 

When  a  piece  of  carbon  steel  is  pressed  against  a  rapidly 
running  emery  wheel,  there  is  given  off  a  shower  of  brill- 
iant sparks  which  flash  out  in  innumerable  white,  tiny 
stars  of  great  beauty;  it  is  accepted  that  this  brilliancy  is 
due  to  the  explosive  combustion  of  particles  of  carbon. 

When  a  steel  containing  as  much  as  three  per  cent  of 


30  STEEL: 

tungsten  is  pressed  against  the  wheel,  the  entire  absence  of 
these  brilliant  flashes  is  at  once  noticeable,  and  if  there  be 
an  occasional  little  flash  it  only  serves  to  emphasize  the 
absence  of  the  myriads. 

Instead  there  is  an  emission  of  a  comparatively  small 
number  of  dull  particles,  and  there  is  clinging  to  the 
wheel  closely  a  heavy  band  of  a  deep,  rich  red  color. 
This  red  streak  is  distinctive  of  the  presence  of  tungsten. 

By  testing  various  pieces  it  was  soon  observed  that  dif- 
ferent quantities  of  tungsten  gave  different  sizes  of  red 
streaks;  as  tungsten  decreased  the  width  of  the  band  di- 
minished and  the  number  and  brilliancy  of  carbon  sparks 
increased.  As  little  as  .10  tungsten  will  show  a  fine  red 
line  amidst  a  brilliant  display  of  sparks,  and  it  soon  be- 
came possible  to  determine  so  closely  by  the  streak  the 
quantity  of  tungsten  present  that  the  ordinary  analyses 
for  tungsten  became  unnecessary,  except  in  occasional 
important  cases  where  analysis  was  used  merely  to  confirm 
the  testimony  of  the  wheel. 

Self-hardening  steel,  then,  is  a  steel  which,  owing  to 
the  presence  of  manganese  and  tungsten,  hardens  when 
quenched  in  quiet  air,  and  which  retains  its  hardness 
almost  up  to  a  red  heat. 

It  may  be  forged  between  the  temperatures  from  orange 
to  bright  orange;  it  cannot  be  worked  safely  outside  of 
this  range.  The  more  quickly  it  is  quenched  the  harder 
it  will  be;  and  it  may  be  annealed  so  that  it  can  be  ma- 
chined readily.  Therefore  it  is  not  self-hardening;  it 
simply  has  all  of  the  properties  of  carbon  steel  modified 
profoundly  by  tungsten  and  manganese.  If  a  piece  of 
this  steel  will  not  harden  sufliciently  by  cooling  in  the  air 
quietly,  that  difficulty  may  be  remedied  by  cooling  it  in 


A   MANUAL   FOR   STEEL-USERS.  31 

an  air-blast;  if  quenching  in  an  air-blast  will  not  give 
sufficient  hardness,  the.  steel  had  better  be  rejected,  for 
quenching  in  oil  or  water  means  almost  certain  destruction. 

As  stated  before,  the  range  of  temperature  in  which  self- 
hardened  steel  can  be  forged  safely  is  much  smaller  than 
for  a  high-carbon  steel;  it  is  harder  at  this  heat  than  car- 
bon steel  and  not  so  plastic,  so  that  it  requires  more  care 
and  more  heats  in  working  it  to  tool-shapes. 

This  steel  is  so  sensitive  that  it  often  occurs  in  redress- 
ing it  that  it  will  crumble  at  a  heat  that  was  all  right  in 
the  first  working.  This  difficulty  may  be  remedied  by 
first  cutting  off  the  shattered  part  with  a  sharp  tool,— it 
must  be  cut  hot, — then  heating  the  piece  up  to  nearly  a 
lemon  color,  heating  it  through  without  soaking  it  in  the 
fire,  and  then  allowing  it  to  cool  slowly  in  a  warm,  dry 
place.  After  this  treatment  the  steel  may  be  heated  and 
worked  as  at  first.  This  treatment  does  not  anneal  the 
steel  soft,  because  the  heat  is  not  continued  long  enough, 
and  the  cooling  is  not  sufficiently  slow;  it  does  relieve  the 
strains  in  the  steel,  so  that  it  is  plastic  and  malleable. 

This  treatment  is  good  in  any  high  steel  which  has  be- 
come refractory  from  previous  working. 

Self-hardened  steel  is  not  as  strong  in  the  hardened  con- 
dition as  good  high-carbon  steel;  it  has  not  been  used  suc- 
cessfully for  cutting  chilled  cast  iron,  for  instance.  If 
made  hard  enough  to  cut  a  chill,  it  is  so  brittle  that  the 
cutting-edge  will  crumble  instead  of  cutting;  if  the  temper 
be  let  down  enough  to  stop  the  crumbling,  the  steel  will  be 
softer  than  the  chill,  and  the  edge  will  curl  up  instead  of 
cutting. 

Owing  to  the  retention  of  hardness  at  a  higher  temper- 
ature than  carbon  steel  will  bear  this  steel  is  capable  of 


3$  STEEL: 

doing  a  great  amount  of  work  at  high  speed,  so  that  for 
much  lathe-work  it  is  cheap  at  almost  any  price. 

Owing  to  its  brittle,  friable  nature  its  use  is  limited  to 
the  simpler  forms  of  tools,  and  to  a  narrower  range  of  work 
than  is  possible  with  carbon  steel. 

CHROME    STEEL. 

An  alloy  of  chromium  with  carbon  steel  has  been  before 
the  public  for  many  years,  and  greater  claims  have  been 
made  for  it  than  experience  seems  to  justify.  Chrome  teel 
is  fine-grained  and  very  hard  in  the  hardened  state,  and  it 
will  do  a  large  amount  of  work  at  the  first  dressing;  upon 
redressing  it  deteriorates  much  more  rapidly  than  carbon 
steel  and  becomes  inferior;  it  is  believed  that  this  is  due 
to  a  rapid  oxidation  of  the  chromium. 

It  is  claimed  for  it  that  it  will  endure  much  higher  heats 
without  injury  than  carbon  steels  of  the  same  temper.  In- 
tending purchasers  will  do  well  to  satisfy  themselves  upon 
these  points  before  investing  too  heavily. 

SILICON    STEEL. 

Steel  containing  two  to  three  per  cent  of  silicon  was  put 
upon  the  markets,  and  great  claims  were  made  for  it. 

It  is  exceedingly  fine-grained  and  hardens  very  hard;  it 
is  brittle,  much  more  liable  to  crack  in  hardening  than 
ordinary  steel,  and  it  is  not  nearly  so  strong  as  carbon  steel. 

It  is  made  cheaply  enough  as  far  as  melting  goes,  but  it 
may  not  be  melted  dead,  and  therefore  sound,  because  long- 
continued  high  heat  will  destroy  it;  therefore  the  ingots 
are  more  honeycombed  than  well-melted  carbon-steel  in- 
gots. The  steel  will  not  bear  what  is  known  as  a  welding- 
heat  in  steel-working;  it  is  hot  short;  for  this  reason  the 


A   MANUAL   FOR  STEEL-USERS.  33 

bars  are  more  seamy  than  is  usual  in  carbon  steel.  Added 
to  this  the  hot-shortness  makes  it  so  difficult  to  work  that 
the  labor  cost  is  high.  Altogether,  then,  silicon  steel  is 
expensive,  and  it  presents  no  extra  good  qualities  in 
compensation. 

MANGANESE  STEEL. 

The  glassy  hardness,  brittleness,  and  friability  of  ferro- 
manganese  and  of  spiegel-eisen  are  well  known;  these  are 
products  of  the  blast-furnace,  and  the  manganese  ranges  all 
the  way  from  say  10^  up  to  80£. 

Steel  containing  from  1£  to  3#  of  manganese  is  about  as 
brittle  and  almost  as  unworkable  as  spiegel-eisen,  and  a  fair 
deduction  would  be  that  manganese  above  very  small  limits 
will  not  form  any  useful  alloy  with  iron.  Many  a  general 
law  of  nature  has  been  based  upon  much  more  meagre  data 
and  has  been  announced  with  a  great  flourish  of  trumpets: 
such  discoveries  are  usually  heard  of  no  more  after  the  first 
blare  has  died  away. 

R.  A.  IIadfield,of  Sheffield,  England,  is  an  inquirer  who 
wants  to  know,  and  who  is  willing  to  travel  the  whole  road 
in  order  to  find  out.  Hadfield  discovered  that  an  alloy  of 
iron  and  manganese  containing  from  ?#  to  20#  of  man- 
ganese was  a  compound  possessing  many  remarkable  prop- 
erties. This  alloy  is  now  known  as  manganese  steel. 

Manganese  steel  is  both  hard  and  tough  to  a  degree  not 
found  in  any  other  metal  or  alloy. 

It  is  so  hard  and  strong  that  it  cannot  be  machined  with 
the  best  of  tools  made  of  the  finest  steel.  Castings  made 
of  it  may  be  battered  into  all  sorts  of  shapes  as  completely 
as  if  they  were  made  of  the  mildest  dead-soft  steel;  still 
they  are  too  hard  to  be  machined. 


34  STEEL: 

The  ordinary  hardening  process  toughens  this  steel  in- 
stead of  hardening  it  to  brittleuess. 

This  steel  is  non-magnetic,  and  this  property  alone  would 
give  it  exceedingly  great  valut  if  the  steel  could  only  be 
worked  into  the  required  shapes. 

Up  to  this  time  all  attempts  to  anneal  this  steel  have 
failed,  and  this  persistent  hardness  is  the  best  proof  that 
manganese  is  the  real  hardener  in  self-hardened  steel.  >So 
far  carbon  and  manganese  have  not  been  separated  in  this 
steel  or  in  any  other.  Persistent  attempts  have  been  made 
to  produce  manganese  steel  low  in  carbon,  but  all  have  been 
failures,  because  any  operation  that  burned  out  the  carbon 
took  the  manganese  with  it.  The  hope  was  that  a  non- 
magnetic alloy  might  be  produced  that  would  be  soft 
enough  to  work.  This  may  yet  be  accomplished,  and  if  it 
should  be  another  great  step  in  the  arts  will  have  been 
taken. 

Hard,  tough,  strong,  non- magnetic — what  great  things 
may  not  come  out  of  this  when  it  has  been  worked  out 
finally  ? 

Since  this  was  written  carbonless  manganese  has  been, 
produced  which  is  claimed  to  contain  98$  +  of  manganese 
and  no  carbon,  but  at  present  it  is  sold  at  $1  per  pound. 
If  it  can  be  produced  more  cheaply,  it  may  lead  to  a  work- 
able non-magnetic  alloy  of  iron  and  manganese  which 
may  prove  to  be  of  great  value  to  electricians  and  to 
watchmakers. 

The  uses  of  manganese  steel  are  large  and  growing,  and 
it  must  be  regarded  as  having  an  established  and  a  promi- 
nent place. 

It  has  been  stated  that  in  self-hardened  steel  and  in 
manganese  steel  manganese  is  the  hardener;  it  should  be 


A  MANUAL  FOR  STEEL-USERS.  35 

borne  in  mind  that  carbon  is  always  present,  that  it  is  the 
one  great  hardener,  but  its  hardening  property  in  the 
absence  of  manganese  depends  directly  upon  rapidity  of 
cooling.  By  rapid  cooling  steel  containing  carbon  is  made 
harder  than  glass,  and  by  slow  cooling  it  may  be  made 
softer  and  more  ductile  than  ordinary  wrought  iron. 

Self-hardened  steel  may  be  annealed  so  that  it  can  be 
machined,  but  it  is  by  no  means  as  soft  and  ductile  us  well- 
annealed  carbon  steel.  Manganese  steel  has  not  been  an- 
nealed at  all ;  it  cannot  be  annealed  by  any  of  the  well- 
known  annealing  processes;  some  new  way  of  doing  it 
must  be  discovered.  Therefore  it  is  proper  to  say  that 
the  peculiar  hardening  properties  of  these  two  steels  are 
due  to  manganese. 

NICKEL  STEEL. 

The  addition  of  a  few  per  cent  of  nickel  to  mild  steel 
adds  greatly  to  its  strength— so  much  so  that  nickel  steel 
is  now  world-renowned  as  used  in  armor-plate  for  navy 
vessels,  and  for  great  guns.  Recent  reports  from  the  ord- 
nance bureaus  indicate  that  it  will  also  be  of  great  use  in 
the  barrels  of  small  arms,  by  means  of  which  they  may  be 
made  lighter,  and  still  of  sufficient  strength.  Nickel  is  so 
expensive  and  it  adds  so  much  to  the  cost  of  steel  that  its 
use  for  ordinary  structural  purposes,  bridges,  etc.,  has  not 
been  found  to  be  economical. 

Some  years  ago  careful  experiments  were  made  with 
nickel  alloy  in  a  fine  grade  of  high-carbon  tool-steel  to 
find  out  whether  such  steel  would  be  improved  as  much  as 
are  the  mild  steels. 

In  such  case  the  expense  would  not  count,  for  if  the 


36  STEEL: 

best  steel  can  be  made  better  there  are  many  users  who 
would  gladly  pay  a  higher  price  for  a  better  service. 

The  results  were  not  encouraging.  The  high-carbon 
nickel  steel  was  not  as  strong  as  the  same  quality  of 
steel  without  nickel;  the  mixture  seemed  to  be  imperfect, 
containing  little  dark  specks,  supposed  to  be  carbon 
thrown  into  the  graphitic  state.  The  steel  did  not  refine 
as  Avell  and  was  not  as  strong  as  the  carbon  steel. 

All  of  this  applies  to  high-carbon  tool-steel,  hardened 
and  tempered;  no  tests  were  made  of  the  steel  nnhardeiied, 
for  they  would  have  been  of  no  practical  use. 

ALUMINUM    STEEL. 

When  a  heat  of  steel  is  boiling  violently,  is  wild,  and 
unfit  to  be  poured,  the  addition  of  a  minute  quantity  of 
aluminum  will  have  the  effect  of  quieting  it  quickly. 
Half  an  ounce  to  an  ounce  of  aluminum  to  a  ton  of  steel 
will  be  enough  usually,  and  for  this  purpose  aluminum 
has  become  useful  to  steel-makers.  If  a  little  too  much 
aluminum  be  added,  the  ingots  will  pipe  from  end  to  end ; 
therefore  the  use  of  aluminum  is  restricted  to  small  quan- 
tities. Experiments  have  shown  that  a  considerable  per- 
centage of  aluminum  adds  no  good  properties  to  steel; 
therefore  aluminum  steel  so  called  may  be  treated  later 
under  a  different  heading. 


A  MAS  UAL  FOIl  STEEL-USERS.  3? 


IV. 

CARBON. 

OP  all  of  the  abundant  elements  of  nature  carbon  is 
presented  in  the  greatest  variety  of  forms,  and  admits  of 
the  greatest  number  of  useful  applications. 

lu  the  form  of  the  diamond  it  is  the  hardest  of  sub- 
stances, and  is  the  base  used  in  determining  the  compara- 
tive hardness  of  all  others. 

In  the  form  of  graphite  it  is  soft  and  smooth,  and  is  one 
of  the  best  and  most  durable  of  lubricants. 

In  the  form  of  soot  it  is  probably  the  softest  of  solids. 

In  the  form  of  coal  it  is  the  one  great  and  abundant 
fuel  of  the  world,  while  as  graphite  again  it  is  one  of  the 
best  of  refractory  materials. 

Hard,  soft,  highly  combustible,  almost  infusible,  refrac- 
tory, it  lends  itself  to  the  greatest  variety  of  useful  appli- 
cations. To  the  iron-  and  steel-maker  or  worker  it  is 
simply  indispensable;  as  charcoal  or  coke  it  is  the  fuel  of 
the  smelter;  as  gas,  either  carbon  monoxide  or  as  a  hydro- 
carbon, it  is  the  cheapest  and  most  manageable  fuel  for 
melting  and  for  all  operations  requiring  heat. 

As  graphite,  plumbago,  mixed  with  a  little  fire-clay  as  a 
binder,  it  is  the  best  material  for  crucibles  in  which  to 
melt  metals;  as  soot  it  forms  the  best  coating  for  moulds 
into  which  metals  are  to  be  cast. 

Durable  beyond  almost  any  other  substance,  it  would 


38  STEEL: 

make  the  very  best  paiiit  for  metal  structures  if  there  were 
any  known  way  to  make  it  adhere. 


CARBON  IN  IRON. 

Carbon  may  be  introduced  into  iron  in  any  quantity 
from  a  few  hundredths  of  one  per  cent  as  usually  found  in 
wrought  iron,  and  in  what  is  known  as  dead-soft  steel,  up 
to  about  four  per  cent  as  found  in  cast  iron.  By  the  addi- 
tion of  manganese  as  high  as  six  or  seven  per  cent  of  car- 
bon has  been  introduced  into  iron.  Carbon  does  not  form 
a  true  alloy  with  iron,  neither  does  it  form  any  stable 
chemical  compound.  Its  condition  in  iron  seems  to  be  as 
variable  as  it  is  in  nature,  and  sometimes  it  has  been  sup- 
posed to  be  as  capricious  as  it  is  variable.  It  is  hoped  that 
the  reader  of  these  pages  will  find  that  there  is  no  caprice 
about  it,  that  its  action  is  governed  by  as  sure  laws  as  any 
in  nature,  and  that  certain  results  may  be  predicated  upon 
any  treatment  to  which  it  is  subjected. 

The  theories  of  its  actions  are  as  numerous  and  variable 
as  are  the  actions  themselves,  and  they  will  be  treated  in  a 
separate  chapter,  this  chapter  being  confined  to  a  state- 
ment of  known  facts. 

As  stated  in  Chap.  I,  carbon  may  be  introduced  into 
iron  by  heating  carbon  and  iron  in  contact  when  air  is  ex- 
cluded; an J,  conversely,  carbon  is  burned  out  of  cast  iron 
by  the  Bessemer  and  open-hearth  processes  to  reduce  the 
cast  iron  to  cast  steel. 

In  the  crucible  any  quantity  of  carbon  may  be  obtained 
in  steel  by  melting  a  mixture  of  high  blister-steel  and 
wrought  iron,  or  cast  iron  and  wrought  iron,  or  by  charg- 
ing with  wrought  iron  the  necessary  quantity  of  coke  or 


A   MANUAL   FOR  STEEL-USERS.  39 

charcoal.  When  using  plumbago  crucibles,  the  iron  takes 
up  some  carbon  from  the  crucible;  also  the  spiegel-eisen 
or  ferro-manganese  used  adds  some  carbon;  and  for  these 
two  sources  of  carbon  the  melter  allows  when  he  decides 
upon  the  quantity  of  charcoal  needed. 

Results  from  crucible-melting  are  not  strictly  uniform; 
even  if  every  charge  were  weighed  in  a  chemical  balance 
accurately  the  product  would  not  be  uniform,  because  one 
crucible  gives  off  more  carbon  than  another;  in  one  cru- 
cible a  little  more  charcoal  may  be  burned  and  escape  as 
gas  than  in  another;  and  most  variable  of  all,  unless  the 
charcoal  has  been  dried  thoroughly,  is  the  quantity  of 
moisture  in  the  charcoal.  One  charge  of  charcoal  may  be 
dry,  and  the  next  may  contain  as  much  as  twenty-five  per 
cent  of  moisture;  obviously  equal  weights  in  such  a  case 
would  not  give  equal  quantities  of  carbon  to  the  steel. 

In  crucible- steel  this  is  no  disadvantage;  a  skilful  mixer 
will  get  from  ?5#  to  90#  of  his  ingots  of  the  desired  tem- 
per; the  other  ingots  will  all  be  in  demand  for  other  uses, 
and  as  he  can  separate  them  all  with  absolute  certainty  by 
ocular  inspection,  as  described  before,  he  labors  under  no 
fear  of  bad  results. 

In  the  Bessemer  process  it  is  usual  to  burn  out  all  of  the 
carbon  and  then  to  add  the  required  amount  in  the  spiegel; 
for  structural  steels  and  for  rails  this  method  is  satisfac- 
tory. For  high  steel — from  fifty  to  a  hundred  or  more  car- 
bon— the  spiegel  method  does  not  answer  so  well,  because  it 
increases  the  quantity  of  manganese  to  too  great  an 
amount;  higher  carbon  is  then  sometimes  put  in  by  the 
addition  of  a  given  quantity  of  pure  pig  iron  previously 
melted,  or  by  putting  coke  in  the  ladle,  but  this  is  very 
uncertain  on  account  of  the  tendency  of  the  coke  to 


40  STEEL: 

float,  and  be  dissipated  as  a  gas  instead  of  entering  the 

steel. 

The  Darby  method  is  to  place  in  the  way  of  the  stream 
of  steel  as  it  is  poured  from  the  vessel  to  the  ladle  a 
refractory-lined,  funnel-shaped  vessel  filled  with  finely 
divided,  but  not  powdered,  coke.  As  the  stream  rushes 
through  the  coke  it  absorbs  carbon  with  great  rapidity,  and 
it  is  asserted  that  the  currents  and  eddies  formed  in  the 
ladle  by  the  rush  of  the  stream  cause  an  even  distribution 
of  carbon.  That  carbon  will  be  taken  up  in  this  way  is 
certain;  that  a  required  amount,  evenly  distributed,  can  be 
obtained  is  not  so  certain. 

In  the  acid  open-hearth  as  in  the  Bessemer  process  for 
milder  steels  it  is  usual  to  burn  the  carbon  out  almost  en- 
tirely, and  then  to  add  the  desired  amount  with  the  spiegel. 
Higher  carbon  may  be  obtained  by  the  addition  of  pure 
pig  iron,  or  by  using  carbon  bricks  pasted  together  with 
tar  and  weighted  with  iron  turnings;  these  bricks  may  be 
pushed  under  the  surface  in  different  parts  of  the  bath, 
and  in  this  way  the  carbon  can  be  distributed  pretty 
evenly.  In  good  practice  now  the  melt  is  stopped  at  the 
carbon  desired  with  great  success,  thus  saving  time  and 
expense.  In  the  basic  open-hearth  the  melter,  by  the  use 
of  a  little  care  and  good  judgment,  stops  his  melt  at  the 
required  carbon,  and  so  avoids  any  additional  operations, 
unless  his  charge  is  excessively  high  in  phosphorus  and 
his  steel  is  to  be  very  low  in  the  same;  in  that  case  he  may 
have  to  melt  clear  down  and  re-carbonize. 

Steel  of  130  carbon  with  phosphorus  <.05  may  be 
made  on  the  basic  hearth  from  a  charge  containing  10  to 
12  phosphorus  without  melting  below  1.30  carbon. 

If  high-carbon  Bessemer  steel  is  not  uniform,  it  is  not  to 


A   MANUAL   FOR  STEEL- USERS.  41 

bo  wondered  at,  but  as  a  matter  of  fact  it  is  usually  found 
to  be  fairly  uniform,  sufficiently  so  to  work  well. 

If  open-hearth  steel  of  high  carbon  is  not  uniform,  it  is 
clearly  because  the  maker  would  not  take  a  little  trouble 
to  have  it  so. 

Assuming  that  for  convenience  cast  steel  is  graded  for 
carbon  content  by  even  tens,  and  that  the  different  tempers 
are  separated  half-way  between  the  tens,  we  have: 

Carbon. 

.10  including  from    .05  to   .15 

.20  "  "  .16  "    .25 

.30  *  "  .26  "    .35 

.40  "  "  .36  "    .45 

.50  "  "  .46  "    .55 

.60  "  "  .56  "     .65 

.70  "  «  .66  "    .75 

.80  "  "  .76  «    .85 

.90  «  "  .86  "    .95 

1.00  "  "  .96  "  1.05 

1.10  «  «  1.06  "  1.15 

1.20  "  "  1.16  "  1.25 

1.30  "  «  1.26  "  1.35 

1.40  «  "  1.36  "  1.45 

1.50  "  «  1.46  "  1.55 

his  covers  the  usual  commercial  range  from  what  is 
inown  as  dead-soft  steel  up  to  a  high,  lathe-temper  steel. 

Higher  steels  are  used  sometimes,  even  up  to  225  carbon, 
but  they  are  so  exceptional  that  it  is  not  worth  while  to 
continue  the  list  above  150. 

This  list  allows  a  variation  of  .05  carbon  above  and  below 


42  STEEL: 

the  datum  of  each  temper;  some  margin  must  be  had  of 
course,  and  this  is  sufficient  in  the  hands  of  a  careful 
steel-maker;  it  is  found  in  practice  to  be  satisfactory  to 
the  user.  Even  in  the  highest  lathe-steel  where  the  strains 
from  hardening  are  the  greatest,  because  the  change  in 
volume  due  to  a  degree  of  temperature  is  the  greatest,  a 
variation  of  three  or  four  points  above  and  below  the  mean 
does  not  make  enough  difference  in  the  results  to  throw  a 
skilful  temperer  off  from  his  desired  conditions. 

On  the  other  hand,  a  difference  of  a  full  temper  will 
throw  the  most  skilful  worker  off  from  the  track,  and  so 
that  much  variation  is  not  allowable.  For  instance,  if  a 
man  be  working  130  carbon,  and  he  should  receive  a  lot 
of  steel  of  120  carbon,  he  would  get  his  work  too  soft  in 
following  his  regular  methods;  then  if  he  doubted  himself, 
as  he  would  be  apt  to  do,  and  raised  his  heat  to  correct  his 
supposed  aberration,  he  would  get  his  work  too  hard,  coarse- 
grained, and  brittle;  if  he  tried  to  correct  this  by  draw- 
ing to  a  lower  temper  color,  his  tools  would  be  too  soft. 
Again,  if  he  received  a  lot  of  steel  of  140  carbon  and  pro- 
ceeded in  his  regular  way,  he  would  get  a  lot  of  cracked 
tools.  So  that  in  either  case  the  result  would  be  confusion. 
It  is  probable  that  in  almost  any  case  either  120  or  140 
carbon  would  make  a  thoroughly  good  tool  if  the  temperer 
knew  what  he  was  working  with  and  adapted  his  heats  to 
the  carbon.  But  he  does  not  know  of  the  variation,  and 
even  if  he  did  he  would  say,  very  rightly,  that  he  did  not 
propose  to  make  daily  changes  in  his  methods  to  suit  the 
convenience  or  the  carelessness  of  the  steel-maker. 

[t  must  not  be  understood,  however,  that  this  narrow 
range  for  each  temper  limits  the  capacity  of  the  steel;  it 
merely  gives  the  limit' for  regular  easy  working. 


A   MANUAL   FOR   STEEL-USERS.  43 

To  illustrate :  A  good  lathe-tool  may  be  made  of  100-car- 
bou  steel,  aud  of  150  carboii;  but  no  worker  could  use 
these  tempers  indiscriminately,  nor  even  alternately, 
although  he  knew  which  was  which,  because  he  could  not 
change  all  of  his  heats  say  every  five  minutes  and  turn  out 
satisfactory  work.  A  spring  of  given  size,  and  to  carry  a 
given  load,  may  be  made  equally  good  of  GO-carbon  steel 
or  of  140  carbon,  and  such  work  is  done  frequently  in 
shops  that  are  attached  to  steel- works;  but  the  spring- 
maker  must  be  told  beforehand  what  he  is  to  work  with, 
and  he  must  be  given  enough  of  one  kind  of  steel  to 
make  say  a  day's  work,  so  that  he  can  go  along  regularly. 
The  springs  will  be  good,  but  the  one  containing  140  carbon 
will  have  the  highest  elasticity  and  the  most  life,  although 
both  will  have  the  same  modulus  of  elasticity.  The  spring- 
maker  who  buys  his  steel  will  not  submit  to  any  such  varia- 
tions, and  he  ought  not  to  be  asked  to  do  it,  because  one 
temper  of  steel  costs  no  more  than  another,  and  the  select- 
ing out  and  separating  the  tempers  is  only  a  matter  of  a 
little  care. 

Is  it  practicable  to  keep  steel  uniform  in  carbon  within 
such  narrow  limits  ? 

In  crucible-steel  practice  it  is  very  easy  to  do  so.  All  in- 
gots of  60  carbon  upwards  up  to  four  or  four  and  one 
half  inches  square  may  be  broken  completely  off  at  the  top, 
and  then  the  clean  fracture  will  indicate  the  quantity  of 
carbon  invariably,  and  after  the  ingot  has  been  glanced  at 
and  marked  properly  it  is  as  easy  to  put  it  on  its  proper 
pile  as  to  put  it  on  any  other.  In  a  good  light  a  compe- 
tent inspector  will  mark  thirty  or  forty  ingots  per  minute 
and  do  it  correctly;  it  is  as  easy  to  the  trained  eye  as  it  is 
to  read  a  printed  page. 


44  STEEL: 

This  inspection  is  so  important  that  it  should  never  be 
neglected.  It  is  not  costly,  much  less  than  a  dollar  a 
ton. 

With  larger  ingots  only  a  piece  can  be  broken  off  from 
the  edge,  but  if  the  topper  does  his  work  properly,  enough 
can  be  taken  off  to  show  the  temper  clearly.  Large  ingots 
containing  the  contents  of  a  number  of  crucibles  are  liable 
to  unevenuess  of  temper  from  having  uneven  mixtures  in 
the  pots'and  from  bad  teeming  into  the  moulds;  this  can  be 
detected  usually  in  the  ingot  inspection,  and  if  not  it  can 
be  found  later  during  another  inspection.  Such  variations 
are  often  called  segregations.  This  question  of  segregation 
will  be  discussed  in  a  future  chapter. 

In  the  Bessemer  and  the  open-hearth  practice  ocular 
inspection  of  ingots  to  determine  carbon  is  not  used. 

Enough  examinations  have  been  made  to  show  that  the 
fractures,  although  differing  from  those  of  crucible-steel, 
are  quite  as  characteristic,  and  ocular  inspection  could  be 
used.  The  ingots  are  large  usually  and  to  handle  and  top 
them  would  be  expensive;  but  the  heats  are  also  large, — 
from  five  tons  up  to  thirty  tons  in  one  heat, — and  as  they 
are  supposed  to  be  homogeneous,  one  chemical  carbon 
analysis  is  enough  for  each  heat. 

Below  50  carbon  a  quick  color  analysis  is  accurate  enough ; 
above  50  carbon  combustion  should  be  used,  for  in  high 
carbons  the  color  test  in  the  best  hands  is  only  the  wildest 
guess-work. 

The  ten-point  range  of  carbon  is  far  more  difficult  to 
attain  in  high-carbon  open-hearth  practice  than  in  the 
crucible.  In  one  case  where  the  limit  fixed  in  a  specifica- 
tion was  90  to  110  carbon,  two  full  tempers,  one  of  the 
most  skilful  and  successful  concerns  in  the  world  failed  to 


A   MANUAL   FOR   STEEL-USERS.  45 

meet  the  specification  in  twenty-ton  and  thirty-ton  fur- 
naces. 

It  was  supposed  at  first  that  the  trouble  came  from  using 
different  heats,  and  large  lots  of  billets  were  sent  out  with 
the  heat  number  stamped  on  each  billet.  The  same  varia- 
tions were  found  in  every  heat,  the  carbon  ranging  from 
80  to  120.  The  specification  was  met  without  any  trouble 
in  five-ton  furnace. 

This  illustration  should  not  lead  to  the  conclusion  that 
practically  uniform  steel  cannot  be  obtained;  th'ere  is  little 
doubt  that  if  the  30-ton  heats  had  been  stirred  thoroughly 
in  the  furnace  the  required  limits  would  have  been  obtained. 

Neither  is  it  to  be  understood  that  the  same  variation 
would  occur  in  mild  steel  under  30  carbon.  A  call  for  20 
carbon  would  not  result  in  steel  ranging  from  below  10  to 
above  30, — such  a  result  would  show  gross  carelessness  on 
the  part  of  the  melter,— the  variation  would  go  by  per- 
centage; thus  the  variation  in  the  high  steel  is  from  15# 
below  to  15#  above  the  mean  of  100,  or  even  as  much  as 
20#. 

If  20-carbon  steel  be  required,  a  variation  of  20#  would 
give  a  range  from  16  to  24  carbon,  or  well  within  the 
limits  of  one  temper. 

This  matter  will  be  considered  farther  under  the  head 
of  Segregation. 

The  appropriate  applications  of  the  different  tempers  of 
steel  have  been  stated  in  a  general  way,  with  the  advice 
that  for  all  tool  purposes  it  is  better  to  leave  the  selection 
of  the  temper  to  the  steel-maker;  also  in  structural  work 
it  may  prove  to  be  better  to  leave  the  question  of  temper, 
or  carbon  content,  to  the  steel-maker,  who  should  know 


46  STEEL : 

how  to  meet  any  specification  that  is  within  the  capacity 
of  steel.  On  the  other  hand,  every  engineer  should  know 
what  is  attainable,  and  an  effort  to  give  this  information  in 
more  definite  form  will  be  made  in  later  chapters.  A  gen- 
eral view  will  now  be  taken  of  what  may  be  called  the 
carbon-line. 


Let  the  horizontal  line  represent  iron,  the  inclined  line 
iron  plus  carbon,  and  the  verticals  physical  properties. 

We  do  not  know  the  physical  properties  of  pure  iron. 
Assuming  them  to  be  uniform, let  the  vertical  at  .05  repre- 
sent the  tensile,  torsional,  transverse,  or  compressional 
strength  of  steel  of  5  carbon;  then  for  every  increment  of 
carbon  np  to  90  to  100  there  will  be  an  increase  of  strength 
to  resist  any  of  these  strains,  increasing  in  such  regular 
amounts  as  to  make  the  resulting  carbon-line  practically 
straight,  as  shown  in  the  sketch.  Above  100  carbon  these 
resistances  will  all  decrease,  except  resistance  to  compression. 

So  far  as  it  is  known,  compressive  strength  increases 
slightly  with  the  carbon,  until  cast  iron  is  fairly  reached; 
then  the  presence  of  silicon,  and  the  fact  that  we  are  deal- 
ing with  a  casting  instead  of  forged  or  rolled  metal,  causes 
a  rapid  fall  in  all  resistances  until  the  strength  is  below 
that  of  5-carbon  steel. 

With  increase  of  carbon  there  is  a  reduction  of  ductility, 
so  that  the  extension  of  length  and  reduction  of  area 


A   MANUAL   FOR  STEEL-USERS.  47 

decrease  as  the  strength  increases.  In  every  case  the  engi- 
neer must  decide  how  little  ductility  he  can  do  with  safely 
in  securing  the  ultimate  strength  or  the  elastic  limit  he 
may  require. 

The  highest  strength  and  the  greatest  ductility  cannot 
be  had  together;  they  are  inverse  functions  one  of  the 
other. 

If  the  exact  resistances  due  to  carbon  were  known  along 
the  whole  line,  it  would  be  of  great  value  to  give  them  here 
but  nearly  all  of  the  thousands  of  tests  published  are  in- 
fluenced by  the  quantities  of  silicon,  phosphorus,  sulphur, 
manganese,  or  oxides  present,  and  an  effort  to  determine 
the  effects  of  the  carbon-line  exactly  would  be  hazardous. 

Kirkaldy's  tests  of  Fagersta  steel,  published  in  1876, 
furnish  a  valuable  guide  in  this  direction. 

Webster's  experiments  on  the  effects  of  the  different 
elements,  phosphorus,  manganese,  etc.,  are  interesting  and 
valuable,  but  he  has  not  yet  tested  a  complete  carbon-line 
with  no  other  variables. 

It  has  been  stated  time  and  again  by  experienced  steel- 
makers that  the  best  steel,  the  most  reliable  under  all  cir- 
cumstances, is  that  which  comes  nearest  to  pure  iron  and 
carbon. 

Some  intelligent  steel-makers,  and  engineers  cast  doubts 
upon  this  statement,  and  assert  that  because  phosphorus 
up  to  a  certain  limit,  or  manganese,  or  silicon,  or  in  fact 
it  may  be  said  almost  any  element,  added  to  dead-soft  steel 
will  give  an  increase  of  strength,  therefore  the  presence 
of  one  or  more  of  these  elements  is  not  only  not  harmful, 
but  beneficial. 

As  a  matter  of  fact,  however,  every  one  of  these  elements 
is  harmful,  either  in  producing  cold-shortness,  or  red-short- 


48  STEEL: 

ness,  or  brittleness,  and  not  one  of  them  will  add  any  good 
quality  to  steel  that  may  not  be  obtained  better  by  the  use 
of  carbon,  (iiven  a  uniform  minimum  content  of  these 
impurities,  the  carbon-line  may  be  depended  upon  to  fur- 
nish any  desirable  quality  that  is  obtainable  in  steel;  and 
it  is  certain,  always  sure,  that  that  steel  which  is  the  near- 
est to  pure  carbon  and  iron  will  endure  the  most  punish- 
ment with  the  least  harm. 

That  is  to  say,  that  such  a  steel  when  overheated  a  little, 
or  overworked,  or  subjected  to  any  of  the  irregularities  that 
are  inevitable  in  shop  practice,  will  suffer  less  permanent 
harm  than  a  steel  of  equal  strength  where  there  is  less  car- 
bon and  the  additional  strength  is  given  by  any  other 
known  substance. 

It  is  difficult  to  show  this  from  testing-machine  data, 
indeed  it  is  doubtful  if  any  such  data  exist,  but  experience 
in  the  steel-works,  in  the  bridge-  and  machine-shops,  and 
in  the  field  proves  it  to  be  true.  For  further  discussion  of 
this  question  see  Chap.  X. 

The  effects  of  a  small  difference  in  phosphorus  or  in 
silicon  contents  are  shown  plainly  and  unmistakably  in 
high-carbon  steel,  and  not  so  plainly  in  low-carbon  steel; 
but  as  there  is  no  known  hard  and  fast  line  that  divides 
low  steel,  medium  steel,  and  high  steel,  so  there  is  no 
marked  difference  in  their  properties.  The  same  rules 
hold  all  along  the  line,  the  same  laws  govern  all  of  the  way 
through. 

There  is  no  set  of  properties  peculiar  to  low  steel  and 
another  set  peculiar  to  high  steel;  the  same  laws  govern 
all,  and  differences  are  those  of  degree  and  not  of  law. 

Given  three  samples  of  steel  of  the  following  composi- 


A  MANUAL  FOR  STEEL-USERS.  49 

No.  1.        No.  2.         No.  3. 

Silicon 02  .20  .02 

Phosphorus 01  .01  .02 

Sulphur 005  .005  .005 

Manganese 100  .100          .100 

Carbon 1.100  1.100  1.100 

A  skilful  worker,  not  knowing  the  composition  of  any, 
will  pick  them  out  invariably  by  tempering  them  and  test- 
ing them  with  a  hand-hammer  and  by  inspecting  the  frac- 
tures. 

He  will  pronounce  No.  1  to  be  the  best  and  the  strongest 
in  every  way;  No.  2  to  be  not  quite  as  strong  as  No.  1,  and 
more  liable  to  crack  from  a  little  variation  in  heat;  No.  3 
to  be  riot  so  strong  as  No.  1,  and  that  it  will  not  come 
quite  as  fine  as  either  of  the  others,  and,  like  No.  2,  it  will 
not  stand  as  much  variation  in  heat  as  No.  1. 

Give  a  ton  of  each  to  a  skilful  axe-rnaker,  from  which  he 
will  make  one  thousand  axes  of  each,  and  he  will  be  sure 
to  report  No.  1  all  right;  No.  2  good  steel,  more  loss  from 
cracked  axes  than  in  No.  1. 

No.  3  good  steel,  some  inclination  to  crack;  it  will  not 
refino  as  well  as  No.  1  and  is  not  as  strong. 

This  is  no  guess-work,  nor  is  it  a  fancy  case;  it  is  simple 
fact,  borne  out  by  long  experience. 

Give  a  skilful  die-maker  one  hundred  blocks  of  each  to 
be  made  into  dies.  He  will  not  break  one  of  No.  1  in 
hardening  them;  he  will  probably  break  five  to  ten  of  No. 
2;  and  if  he  breaks  none  of  No.  3 — a  doubtful  case— he 
will  find  in  use  that  No.  I  will  do  from  twice  to  twenty 
times  as  much  work  as  either  of  the  others.  If  he  is  mak- 
ing expensive  dies, — many  dies  cost  hundreds  of  dollars 


50  STEEL: 

each  for  the  engraving, — he  will  think  No.  1  cheap  at 
25  cents  a  pound,,  and  either  of  the  others  dear  at  15  cents 
a  pound. 

In  such  steel,  then,  the  absence  of  a  few  points  of  silicon, 
or  of  a  point  or  two  of  phosphorus,  is  worth  easily  10  cents 
a  pound. 

Now  let  the  carbon  in  these  three  steels  be  reduced  to  10, 
making  them  the  mildest  structural  steel.  The  differences 
to  be  found  in  the  testing-machine  in  tensile  strength, 
elastic  limit,  extension,  and  reduction  of  area  will  be 
almost  or  altogether  nothing;  in  forging,  flanging,  punch- 
ing, etc.,  under  ordinary  conditions  differences  would  not  be 
observable;  therefore  there  would  be  no  practical  difference 
in  value.  But  let  the  silicon  be  raised  to  30  or  the  phos- 
phorus to  10, — the  Bessemer  limit, — or  let  both  be  raised 
together,  and  both  the  testing-machine  and  shop  practice 
would  show  a  marked  difference. 

This  shows  that  in  the  absence  of  carbon  the  action  of 
these  elements  is  sluggish  as  compared  to  their  effects  in 
the  presence  of  high  carbon,  or  in  the  low-carbon  steels 
their  effects  are  not  so  observable.  That  their  influence  is 
there,  there  can  be  no  doubt,  but  if  it  be  not  enough  to 
endanger  the  material  it  is  not  worth  while  to  take  it  into 
account. 

Is  it  safe  and  wise,  then,  for  steel-users  to  ignore  composi- 
tion ? 

Users  of  tool-steel  may  do  so  safely,  because  the  smallest 
variations  will  manifest  themselves  so  unmistakably  that 
they  give  immediate  warning,  and  the  steel-maker  must 
keep  his  product  up  to  a  rigid  standard  of  excellence  or 
lose  his  character  and  his  trade.  Many  of  the  ablest  users 
of  structural  steel  take  a  similar  ground,  and  say,  We 


A  MANUAL  FOR  STEKL-USERS.  51 

have  nothing  to  do  with  method  or  composition  if  the 
material  meets  our  tests. 

It  is  believed  that  if  these  men  knew  how  easy  it  is  for  a 
skilful  worker  to  doctor  temporarily  an  off  heat  by  a  little 
manipulation,  and  how  dangerous  the  same  may  become 
by  a  little  off  practice  in  the  field,  they  would  be  convinced 
that  some  limits  should  be  put  upon  composition,  espe- 
cially if  they  could  realize  that  a  reasonable  specification 
would  add  nothing  to  cost,  as  competition  would  take  care 
of  that. 

The  reader  is  referred  again  to  Chap.  X  011  impurities. 


52  STEEL: 


V. 

GENERAL  PROPERTIES  OF  STEEL. 

STEEL  is  very  sensitive  to  heat.  In  general  it  may  be  stated 
that,  starting  with  cold  steel,  every  degree  of  heat  added 
causes  a  change  in  size  and  in  structure,  until  the  limit  is 
reached  where  disintegration  begins.  The  changes  are  not 
continuous;  there  are  one  or  two  breaks  in  the  line,  notably 
at  the  point  where  we  have  what  is  called  recalescence;  this 
is  a  marked  phenomenon  and  it  will  be  considered  later. 

The  effects  of  heat  are  permanent,  so  that  it  is  a  fact 
that  every  variation  of  temperature  which  is  marked  enough 
to  be  visible  to  the  naked  eye  will  leave  a  structure,  due  to 
that  variation,  when  the  steel  is  cold,  which  will  be  observ- 
able by  the  naked  eye,  and  such  structure,  when  not 
influenced  by  external  force,  such  as  by  hammering  or 
rolling,  is  as  invariable  and  certain  as  is  the  structure  of  an 
ingot  due  to  the  quantity  of  carbon  present. 

This  property  furnishes  what  may  be  called  the  steel- 
maker's and  the  steel-user's  thermometer.  By  its  means 
the  steel-maker  can  discover  every  irregularity  in  heating 
that  may  have  been  perpetrated  by  the  operatives;  so  also 
the  steel-user  can  decide  whether  the  steel  furnished  him 
has  been  heated  and  worked  uniformly  and  properly,  and 
later  he  can  tell  whether  those  who  have  shaped  this  steel 
to  its  final  forms  have  done  their  work  properly.  A 
thorough  knowledge  of  this  property  is  essential  to  a  steel- 


A  MANUAL   FOR   STEEL-USERS.  53 

maker;  until  he  possesses  it  he  is  not  fit  to  conduct  his 
business.  It  is  of  great  importance  to  the  steel-user,  and 
every  engineer  should  try  to  acquire  a  knowledge  of  it  in 
order  that  he  may  not  be  fooled  by  the  carelessness  or  ras- 
cality of  those  who  have  preceded  him.  The  steel-maker 
acquires  this  knowledge  by  daily  contact  with  the  facts; 
the  engineer  does  not  have  it  forced  upon  him  in  this  way, 
but  he  should  seek  opportunities  of  observation,  which  will 
be  abundant  in  his  earlier  practice  when  he  is  sent  upon 
inspection  duty.  Like  the  structure  of  ingots,  this  heat- 
structure  cannot  be  illustrated  on  paper,  and  an  attempt  to 
do  so  would  be  misleading;  attempts  at  description  will  be 
made  in  the  hope  that  by  their  means  the  engineer  will 
have  a  pretty  good  idea  what  to  look  for,  and  to  know  when 
his  suspicions  should  be  aroused. 

In  addition  to  the  ocular  observations  mentioned  it  has 
been  shown  by  specific-gravity  determinations,  and  by 
delicate  electrical  tests  through  small  ranges  of  teinpera- 
ature,  that  steel  is  as  truly  thermometrical  as  mercury. 

Steel  passes  through  or  into  four  general  conditions  due 
to  heat.  First,  in  the  cold  state,  it  is  a  crystalline  solid  of 
no  uniform  structure,  for  its  structure  is  influenced  by 
every  element  that  enters  into  it,  and  by  every  irregularity 
of  heat  to  which  it  has  been  subjected. 

Good  steel  may  be  described  as  having  a  bluish-gray 
color,  uniform  grain  as  seen  by  the  naked  eye,  and  little 
lustre.  But  it  should  have  some  lustre  and  a  silky  appear- 
ance. When  it  is  right,  a  steel-worker  will  say  it  is  "  sappy," 
and  that  name,  absurd  as  it  may  sound  when  applied  to  a 
metal,  really  expresses  an  appearance,  and  implies  an  ex- 
cellence that  it  would  bo  hard  to  find  a  better  word  for. 
If  the  structure  be  dull  and  sandy-looking,  the  steel-worker 


54  STEEL: 

will  say  it  is  "dry,"  ami  that  term  is  as  suggestive  and  ap- 
propriate as  the  word  "sappy." 

If  the  fracture  be  granular  with  bright,  flashing  lustre, 
the  steel- worker  will  say  it  is  "  fiery,"  and  again  his  term 
is  expressive  and  proper. 

It  is  perfectly  safe  to  say  that  steel  of  a  "  sappy  "  ap- 
pearance is  good  steel;  but  in  order  to  know  what  it  is  it 
must  be  learned  by  observation,  it  cannot  be  described  in 
exact  terms. 

It  is  equally  certain  that  a  "  dry  "  fracture  indicates  a 
mean  steel,  a  steel  inherently  mean, — too  much  phosphorus, 
or  silicon,  or  oxides,  or  all  combined,— and  such  a  steel  is 
incurable. 

A  "  fiery  "  fracture  indicates  too  much  heat.  It  may  be 
found  in  the  best  steel  and  in  the  poorest;  it  may  be  cor- 
rected by  simply  heating  to  a  proper  temperature.  It 
shows  that  some  one  needs  to  be  reprimanded  for  careless 
work. 

If  now  an  inquirer  will  take  a  piece  of  good  steel  of 
"  sappy  "  fracture,  and  of  "  dry"  steel  of  dull,  sandy  frac- 
ture of  the  same  carbon,  and  will  heat  them  say  first  to 
dark  orange,  then  to  bright  orange,  dark  lemon,  and  so  on, 
and  examine  the  fractures  after  each  heating,  he  will 
find  a  "  fiery  "  fracture  in  the  "  dry  "  steel  at  a  heat  much 
below  that  which  is  necessary  to  make  the  "  sappy  "  steel 
"fiery."  This  is  one  proof  that  good  steel  will  endure 
more  punishment  than  poor  steel. 

Cold  steel  is  not  plastic  in  the  common  acceptance  of 
the  word ;  strictly  speaking  it  has  some  plasticity,  as  shown 
in  the  extension  noted  in  pulling  it;  this  is  its  measure  of 
ductility. 

Also  it  may  be  drawn  cold  to  fine  wire  of  only  a  few 


A  MANUAL   FOR  STEEL-USERS.  55 

thousandths  of  an  inch  in  diameter,  and  it  has  been  rolled 
cold  to  one  five  thousandth  of  an  inch  thick.  But  this 
work  must  be  done  with  great  care;  the  steel  soon  becomes 
brittle,  and  a  little  overdrawing  or  overrolling  will  crush 
the  grain  and  ruin  the  steel;  therefore  the  work  must  be 
done  a  little  at  a  time,  and  be  followed  by  a  careful  anneal- 
ing. 

To  reduce  a  No.  5  wire  rod  to  .005  inch  diameter  will  re- 
quire with  high  steel  suitable  for  hair-springs  about  four- 
teen annealings. 

A  skilful  hammerman  will  take  a  piece  of  mild  cold 
steel,  and  by  means  of  light,  rapid  blows  he  will  heat  it  up 
to  a  bright  lemon  heat  without  fracturing  it;  then  he  will 
have  it  thoroughly  plastic  and  malleable. 

This  has  no  practical  commercial  value;  it  is  a  beautiful 
scientific  experiment  exhibiting  high  manual  skill,  and 
showing  that  there  is  no  hard  and  fast  line  between  non- 
plasticity  and  plasticity. 

The  first  condition,  then,  is  cold  steel,  not  plastic,  not 
malleable. 

When  steel  is  heated,  it  begins  to  show  color  at  about 
700°  to  800°  F.;  the  first  color  is  known  as  dark  cherry 
red,  or,  better^  orange  red ;  above  tins  color  it  turns  to  a 
distinct,  rather  dark,  or  medium  orange  color;  this  is  the 
heat  of  recalescence,  a  good  forging-heat.  and  the  best  an- 
nealing- and  quenching-heat.  At  this  heat  and  above  it 
good  steel  is  truly  plastic  and  malleable;  a  roller  or 
hammerman  will  say,  "  It  works  like  wax,"  and  so  it 
does. 

This  is  the  second  or  plastic  condition. 

Heated  above  this  plastic  condition  to  a  bright  lemon  in 
high  steel,  or  to  a  creamy,  almost  scintillating,  heat  in  mild 


56  STEEL: 

steel,  steel  will  go  to  pieces  under  the  hammer  or  in  the 
rolls;  the  workman  will  probably  say  it  is  burned,  but  it 
is  not  burned  necessarily;  it  is  simply  heated  up  to  the 
third  or  granular  condition;  it  is  the  beginning  of  disin- 
tegration and  the  end  of  plasticity. 

This  granular  condition  is  important  in  several  ways. 
It  is  made  use  of  in  Sweden,  and  has  been  demonstrated 
iu  the  United  States,  to  determine  the  quantity  of  carbon 
in  steel.  An  intelligent  blacksmith  is  given  a  set  of  rods 
of  predetermined  carbon,  ranging  from  100  carbon  to 
zero,  or  through  any  range  that  may  be  necessary;  each 
rod  is  marked  to  indicate  its  carbon.  He  takes  the  rods 
one  by  one  and  heats  them  until  they  scintillate,  well  up 
into  the  granular  condition,  then  lays  them  on  his  anvil 
and  hammers  them,  observing  carefully  the  color  at  which 
each  one  becomes  plastic  as  it  cools  slowly.  After  a  little 
practice  he  is  given  rods  that  are  not  marked,  and  by 
treating  them  in  the  same  way  he  will  give  them  their 
proper  numbers,  rarely  missing  the  carbon  by  as  much  as 
10  points,  or  one  temper. 

It  is  a  beautiful  and  useful  illustration  of  the  effect  of 
carbon.  The  rule  is,  the  higher  the  carbon  the  lower  the 
granulating-point;  or,  as  is  well  known,  high  steel  will 
melt  at  a  lower  temperature  than  low  steel. 

This  shows  that  every  temper  of  steel  has  its  disintegra- 
tion temperature  where  it  passes  from  plastic  to  granular, 
as  fixed  as  its  fusion-point  or  its  point  of  recalescence. 

Steel  passes  from  the  granular  condition  to  the  liquid  or 
fourth  form. 

There  is  little  of  interest  in  the  liquid  condition  of  steel 
to  any  but  the  steel-maker;  what  there  is  to  be  said  will  be 
mentioned  later. 


A   MANUAL    FOR   STEEL-USERS.  57 

Steel  in  cooling  from  the  liquid  passes  through  the 
granular  and  the  plastic  conditions  to  the  cold  state. 

The  granular  lorra  is  of  special  interest  to  the  steel- 
maker for  the  reason  that  in  this  condition  the  steel  has 
more  of  adhesion  than  cohesion;  it  will  stick  to  anything  it 
touches,  and  so  cannot  be  made  to  flow.  This  is  the  cause 
of  "  bears,"  "  stickers,"  and  many  of  the  troubles  of  the 
melter.  Therefore  steel  must  be  put  into  the  moulds  while 
it  is  still  molten,  and  moulds  should  be  well  smoked  or 
lime-washed  to  prevent  stickers.  This  condition  is  of 
great  interest  to  engineers,  because  the  failure  to  roll  or 
shape  molten  steel  by  pouring  it  directly  between  the 
rolls  is  doubtless  due  to  this  adhesive,  non-cohesive  condi- 
tion. 

To  produce  sheets,  bars,  and  all  sorts  of  shapes  from 
molten  steel  direct,  without  the  expense  of  making,  hand- 
ling, and  re-heating  ingots,  is  an  enticing  idea  which  lias 
occupied  the  minds  and  efforts  of  many  able  mechanics 
and  engineers. 

If  steel  passed  directly  from  the  liquid  to  the  plastic 
condition  as  glass  does,  hammers  and  rolls  would  soon  be 
replaced  by  dies  at  a  great  saving  of  cost  and  labor.  It  is 
no  wonder  that  such  a  desirable  end  has  led  to  many  per- 
sistent and  costly  efforts,  but  until  some  way  can  be  de- 
vised to  eliminate  this  granular  form  in  cooling  it  would 
seem  that  all  such  efforts  must  end  in  failure. 

As  steel  cools  down  through  the  plastic  condition  the 
cooling  is  not  continuous;  there  are  two  or  three  points 
where  it  is  arrested  for  a  time,  and  at  one  notable  point 
the  cooling  is  not  only  arrested,  but  after  a  few  moments  of 
stop  the  operation  is  reversed,  the  steel  becomes  visibly 
hotter,  and  then  the  cooling  goes  on  regularly;  there  may 


58  STEEL: 

be  other  slight  pauses,  but  they  are  of  little  importance 
compared  to  this  one,  which  is  known  as  the  point  of  re- 
calescence.  There  are  many  theories  of  the  cause  of  this 
recalescence;  the  ablest  scientists  are  still  working  at  it; 
and  until  some  definite  conclusion  is  reached  it  is  not 
worth  while  to  write  pages  of  discussion  which  may  be 
found  fully  stated  and  illustrated  over  and  over  again  in 
the  various  technical  journals,  and  transactions  of  different 
engineering  societies. 

There  are  some  properties  of  steel  of  great  interest  which 
seem  to  cluster  around  this  recalesceuce-point;  they  will 
be  noted  as  they  are  reached. 

We  have  seen  that  there  is  a  marked,  definite  structure 
of  the  grain  of  ingots  due  to  every  quantity  of  carbon,  and 
also  that  there  is  a  fixed  limit  of  malleability  for  eveiy 
quantity  of  carbon.  It  is  known  also  that  the  recalescence- 
point  shifts  slightly  with  a  change  of  carbon,  and  that  it 
is  much  more  marked  and  brighter  in  high-carbon  steel 
than  in  low. 

There  are  no  other  sure  indications  of  the  quantity  of 
carbon  present.  As  soon  as  an  ingot  is  heated  up  to 
orange  color,  or  the  recalescent-point,  it  loses  its  distinc- 
tive structure  and  its  fracture  no  longer  furnishes  a  sure 
guide. 

If  three  ingots  of  say,  20,  80,  and  120  -carbon  respec- 
tively be  heated  to  orange  and  then  cooled  slowly,  their 
fractures  will  be  so  different  as  to  enable  an  expert  to 
place  them  properly  in  their  order  of  carbon,  and  to  classify 
them  as  mild,  hard,  and  harder;  beyond  that  he  could  not 
go;  if  he  attempted  to  give  them  their  temper  numbers,  he 
would  be  likely  to  miss  by  four  or  five  numbers  either 
way,  and  a  correct  mark  would  be  only  a  lucky  guess. 


A  MANUAL   FOR   STEEL-USERS.  59 

Hammering  and  rolling  heated  steel  affect  the  grain  or 
structure  profoundly;  a  high  steel  may  be  worked  BO  that 
the  grain  will  look  mild,  and  a  mild  steel  maybe  BO  worked 
that  the  grain  will  look  hard.  It  is  common  to  see  a  bar 
of  steel  with  a  fine  grain  at  one  end  and  a  coarse  grain  at 
the  other,  and  this  state  of  things  often  frightens  a  con- 
sumer, who  imagines  that  he  has  received  a  very  irregular, 
uneven  article,  and  he  is  as  often  astonished  when  it  is 
shown  to  him  that  at  the  same  proper  heat  the  two  ends 
will  refine  and  harden  equally  well,  and  be  exactly  alike. 
In  such  a  bar  one  end  has  been  finished  a  little  hotter  than 
the  other,  and  the  grain  is  due  to  the  heat  in  eacli  case. 
This  uneven  heating  may  have  been  incidental  or  careless; 
with  skilful  workers  it  is  rare. 

One  end  might  have  been  finished  so  cold  as  to  crush 
the  grain,  and  the  other  end  so  hot  as  to  cause  incipient 
disintegration,  but  a  competent  inspector  would  discover 
either  condition  at  once  and  reject  the  bar. 

There  is,  then,  a  specific  structure  due  to  temperature;  it 
is  modified  by  carbon  and  by  treatment  under  the  ham- 
mer or  in  the  rolls.  If  a  bar  of  steel  be  heated  up  to  the 
highest  plastic  limit,  just  so  that  it  will  not  fall  to  pieces, 
and  then  cooled  slowly  without  disturbance,  and  a  frac- 
ture be  taken,  it  will  be  found  to  be  coarse  and  with  an 
exceedingly  brilliant  lustre.  Now  let  it  be  heated  again  to 
a  bright  lemon  color,  but  still  plastic,  and  cooled  as  before; 
it  will  be  found  to  be  coarse,  with  bright  lustre,  but  neither 
so  coarse  nor  so  bright  as  the  first  piece.  Then  let  it  be 
treated  in  this  way  to  lemon  color,  light  orange,  medium 
orange,  dark  orange,  and  orange  red ;  as  the  heats  go 
down  the  grain  will  be  finer  and  the  lustre  will  be  less, 
until  at  about  medium  orange  the  lustre  will  be  absent, 


60  STEEL: 

If  any  number  of  bars  of  even  composition  be  heated  in 
tli is  way,  the  fractures  will  all  be  alike  for  each  tem- 
perature. 

If  a  series  of  bars  of  the  different  full  tempers,  about 
seven  in  all,  be  treated  in  this  way,  the  structures  due  to  a 
given  temperature  will  all  be  similar,  but  there  will  be  no 
two  exactly  alike,  because  high  steel  is  much  more  pro- 
foundly affected  by  heat  than  low  steel. 

Seven  tempers  are  mentioned  here,  because  that  is  the 
number  of  full  tempers  in  common  use.  Steel  is  graded 
out  into  fifteen  tempers  ordinarily  by  the  interpolation  of 
half  numbers;  this  is  easy  and  sure  in  the  ingot  inspection. 
In  the  above  experiment  the  differences  due  to  carbon  are 
not  quite  so  delicate,  and  the  work  is  hampered  in  the 
heating  by  the  personal  equation,  so  that  the  use  of  seven 
full  tempers  is  refinement  enough.  There  is  a  difference 
due  to  every  separable  quantity  of  carbon,  which  could  be 
shown  if  all  of  the  operations  of  the  experiment  were 
exact. 

If  when  a  bar  is  broken  cold  the  fracture  is  uneven, 
with  coarse  grain  in  one  part  and  fine  grain  in  another, 
it  shows  that  there  has  been  uneven  heating.  If  one  side 
has  large  grain  and  the  other  side  is  fine,  the  bar  has  been 
a  great  deal  hotter  on  the  side  having  coarse  grain  than  on 
the  other:  the  heater  has  let  the  bar  lie  in  the  furnace 
with  one  side  exposed  to  a  hot  flame  and  the  other  pro- 
tected from  the  flame  in  some  way;  he  has  neglected  to 
turn  the  bar  over  and  heat  it  evenly. 

If  the  outside  of  the  bar  is  fine  and  the  centre  is  coarse, 
the  bar  has  been  very  hot  all  through  and  has  been  finished 
by  light  blows  of  the  hammer  or  by  light  passes  in  the 
rolls;  it  has  been  worked  superficially  and  not  thoroughly. 


A   MANUAL   FOR   STEEL-USERS.  61 

If  the  outside  of  the  bar  is  coarse  aud  the  centre  is  fine, 
the  steel  lias  been  heated  on  the  surface  too  hot  and  too 
quickly;  it  has  not  had  time  to  get  hot  through,  and  it 
has  had  too  little  work  in  the  finishing. 

If  the  grain  is  dark,  with  the  appearance  of  a  rather 
heavy  india-ink  tint,  the  steel  has  been  finished  too  cold, 
and  it  will  be  found  to  be  brittle. 

If  the  grain  is  very  dark,  especially  about  the  middle, 
looking  almost  black,  then  it  has  been  finished  altogether 
too  cold:  the  grain  is  disintegrated,  and  the  bar  is  fit  only 
for  the  scrap-heap. 

A  bar  of  this  kind  containing  enough' carbon  to  harden 
will  harden  thoroughly,  and  often  appear  to  be  sound  and 
fine,  but  it  is  not  sound  and  will  not  do  good  work;  if  it 
be  brought  up  to  a  proper  heat  and  forged  to  a  point,  it 
will  almost  certainly  burst,  showing  that  the  integrity  of 
the  steel  has  heen  destroyed. 

If  a  bar,  or  plate,  or  beam  shows  cracks  on  the  surface 
or  at  the  corners,  with  rough,  torn  surfaces,  the  steel  has 
either  been  superficially  burned  or  it  is  red-short.  In 
either  case  it  should  be  rejected,  for  the  cracks,  although 
small,  will  provide  starting-points  for  ultimate  fractures, 
whether  it  be  tool-steel  that  is  to  be  hardened,  or  struc- 
tural steel  that  is  to  be  strained  without  hardening.  If 
the  steel  is  to  be  machined,  so  that  all  of  the  cracks  can  be 
cut  out,  then  in  machinery-steel  the  removal  of  these  sur- 
face defects  might  leave  the  finished  piece  sufficiently 
sound  and  good.  If,  however  the  steel  is  to  be  hardened, 
and  the  defects  should  be  due  to  red-shortness,  the  piece 
would  almost  certainly  break  in  the  hardening;  and  if  it 
were  not  red-short,  then  unless  the  cracks  were  cut  away 
entirely,  if  the  least  trace  of  the  crack  is  there,  although 


62  STEEL: 

it  may  not  be  visible,  that  trace  will  be  sufficient  to  start  a 
crack  when  the  piece  is  hardened. 


EFFECTS   OF   COOLING. 

Increase  of  heat  causes  increase  of  softness  up  to  the 
liquid  condition. 

Decrease  of  heat — cooling — increases  hardness  up  to  the 
hardness  of  glass. 

As  an  invariable  rule  the  rate  of  cooling  fixes  the  degree 
of  hardness  to  be  had  in  the  cold  piece  within  the  limits  of 
obtainable  hardness  or  softness. 

Slow  cooling  retains  softness,  so  that  when  annealing  is 
to  be  done  the  slower  the  cooling  the  better.  Cooling  is 
always  a  hardening  process,  but  when  it  is  carried  on  slowly 
more  softness,  will  be  retained  than  when  the  cooling  is 
quick. 

Eapid  cooling  produces  hardness,  and  the  more  nearly 
instantaneous  it  is  the  greater  the  hardness  will  be.  This 
property  of  hardening  is  of  such  extreme  importance  that 
it  will  be  treated  fully  in  a  separate  chapter. 

There  is  an  apparent  exception  to  this  rule  shown  in  the 
operation  called  water-annealing.  It  is  common,  Avhen 
work  is  hurried,  to  heat  a  piece  of  steel  carefully  and  uni- 
formly up  to  the  first  color,  that  is,  until  it  just  begins  to 
show  color,  and  then  to  quench  it  in  water. 

This  is  called  water-annealing;  and  many  believe  that 
because  a  piece  so  treated  is  left  softer  than  it  was  before 
treatment,  the  water-cooling  had  something  to  do  with 
it.  The  fact  is  that  hammering  and  rolling  are  hardening 
processes.  AYhen  the  increment  of  heat  due  to  the  work  is 


A   MANUAL   FOR   STK EL- USERS.  63 

less  than  the  decrement  of  heat  due  to  radiation,  the  com- 
pacting of  the  grain  increases  hardness. 

This  process  leaves  the  piece  harder  than  does  the 
quenching  in  water-annealing;  the  decrease  in  hardness 
due  to  water-annealing  is  the  difference  between  the  effects 
of  the  two  operations.  Let  two  pieces  of  the  same  bar  be 
heated  exactly  the  same  for  water-annealing;  let  one  bo 
quenched  in  water,  and  the  other  be  allowed  to  cool  in  the 
air  in  a  dry  place.  Then  the  superior  softness  of  the  air- 
cooled  piece  will  show  that  the  so-called  water-annealing 
furnishes  no  exception  to  the  rule. 

There  is  one  extremely  important  matter  connected  with 
cooling  that  should  be  noted  carefully. 

It  is  a  common  practice  among  steel-workers  when  they 
get  a  part  of  a  piece  of  steel  too  hot  to  partially  quench 
that  part,  and  then  go  on  with  their  heating;  or  if  they  are 
in  a  hurry  to  get  out  a  big  day's  work,  or  if  the  weather  is 
hot,  and  a  pile  of  red-hot  bars  is  uncomfortable,  to  dash 
water  over  the  pile  and  hurry  the  cooling. 

This  practice  means  checks  in  the  steel,  hundreds  of 
them. 

A  bar  breaks  and  has  this  appearance.    The  dark  spot  is 


the  check:  it  did  not  show  in  the  bar,  no  inspector  could 
see  it,  but  it  broke  the  bar.  Any  one  can  prove  this  to  his 
own  satisfaction  in  a  few  minutes.  Take  a  bar  of  convenient 
size,  about  one  inch  by  one  eighth ;  heat  it  carefully  to  an 


64  STEEL: 

even  medium  orange  color  and  quench  it  completely;  then 
snip  it  with  a  hand-hammer  over  the  edge  of  an  anvil, 
snipping  away  until  satisfied  that  it  is  sound  steel.  There 
are  no  checks. 

Xow  heat  a  similar  length  of  the  same  bar  in  the  same 
way,  and  pass  it  through  the  stream  from  the  bosh-pipe,  or 
submerge  it  for  a  moment  in  the  bosh,  not  long  enough  to 
produce  more  than  the  slightest  trace  of  a  change  in  the 
color;  then  put  it  back  in  the  fire  and  bring  it  gently  to 
the  uniform  color  used  before,  and  quench  it  completely. 
Now  when  it  is  snipped  over  the  anvil  it  will  show  numer- 
ous checks,  dozens  of  them. 

In  this  experiment  the  complete  submersion  for  a  mo- 
ment may  not  produce  checks  at  every  trial,  because  the 
complete  submersion  permits  practically  uniform  cooling, 
which  if  continued  to  complete  cooling  would  be  simplv 
the  ordinary  hardening  process.  Still  it  will  produce  checks 
in  the  majority  of  cases,  indicating  that  starting  the  changes, 
strains,  or  whatever  they  are  of  the  quenching  process  and 
then  stopping  them  suddenly  while  the  steel  is  in  the 
plastic  condition  does  cause  disintegration,  so  that  the 
operation  is  dangerous  and  should  not  be  tolerated.  Pass- 
ing the  hot  steel  through  a  stream  of  water  or  dashing 
water  over  it  must  cause  different  rates  of  cooling,  and 
necessarily  produce  local  strains  resulting  in  checks.  These 
latter  ways  of  injuring,  therefore,  rarely  fail  to  produce  the 
ruinous  checks. 

If  this  positive  destruction  is  produced  in  this  way,  in 
steel  containing  enough  carbon  to  harden  it  is  clear  that 
similar,  although  not  so  pronounced,  results  will  be  produced 
in  the  mildest  steels  when  they  are  treated  in  the  same 
manner. 


A    MANUAL    FOR   STEEL-USERS.  65 

The  rule,  then,  should  be:  Never  allow  water  to  come  in 
coutact  with  hot  steel,  and  never  allow  hot  steel  to  be  la.d 
down  upon  a  damp  floor. 

Even  the  spray  from  water  which  is  run  upon  roll-necks 
may  cause  these  checks  in  steel  that  is  passing  through  the 
rolls,  so  that  it  is  better  to  put  up  a  guard  to  deflect  such 
water  away  from  the  body  of  the  roll. 

A  hammerman  may  sweep  a  bar  with  a  damp  broom  to 
cause  the  vapor  to  explode  with  violence  when  the  ham- 
mer comes  down,  and  so  tear  away  all  rough  scale  and  pro- 
duce a  beautiful  finish.  A  careful,  skilful  man  may  be 
permitted  to  do  this,  but  as  surely  as  he  gets  his  broom 
too  wet,  so  that  drops  of  water  will  fall  on  the  steel  and 
whirl  around  in  the  spheroidal  condition,  just  so  surely  will 
he  check  the  steel. 

The  best  way  is  to  have  the  broom  not  wet  enougb  to 
drip,  and  then  to  strike  it  up  against  the  top  die  when  it  is 
ready  to  descend;  sufficient  moisture  will  be  caught  upon 
the  die  to  cause  a  loud  explosion  when  it  strikes  the  hot 
steel;  it  is  a  violent  explosion  and  will  drive  off  every  par- 
ticle of  detachable  scale,  leaving  as  beautiful  a  surface  as 
that  which  is  peculiar  to  Russia  sheet  iron. 

It  is  common  in  rolling  tires  to  run  jets  of  water  over  the 
tire  to  break  up  the  scale  and  produce  a  clean  surface. 
Tire-makers  assert  that  experience  shows  that  the  water 
does  no  harm.  There  are  two  reasons  for  this  if  it  be  true : 
first,  the  steel  is  of  medium  carbon  and  more  inert  than 
high  steel,  and  it  has  been  hammered  and  compacted 
before  rolling;  second,  the  tires  are  usually  turned,  and 
this  would  cut  away  any  little  checks  that  might  occur  on 
the  surface. 

The  magnetic  properties  of  steel  are  well  known.     Soft 


66  STEEL: 

steel,  like  soft  wrought  iron,  cannot  be  magnetized  perma- 
nently: higher  carbon  steel  will  retain  magnetism  along 
time,  and  hardened  steel  will  retain  it  still  longer.  Hard- 
ened-steel magnets  are  the  most  permanent. 

The  permanency  and  the  efficiency  of  a  magnet  increase 
with  the  quantity  of  carbon  up  to  about  85  carbon;  steel 
of  higher  carbon  than  this  will  not  make  magnets  of  so 
good  permanency.  The  efficiency  of  a  magnet  of  85  carbon 
is  increased  largely  by  the  addition  of  a  little  tungsten;  a 
little  less  than  .05$  is  sufficient. 

It  has  been  shown  that  tungsten  has  the  property  of 
retaining  the  hardness  of  steel  up  to  a  relatively  high  tem- 
perature; this  additional  power  of  retaining  magnetism 
may  indicate  a  close  relation  between  the  conditions  set  up 
by  magnetism  and  by  hardening. 

It  has  been  stated  that  maximum  physical  properties, 
except  as  to  compression,  are  found  at  from  90  to  100 
carbon;  now  we  find  maximum  magnetic  properties  in  the 
same  region.  Prof.  Arnold  has  found  by  microscopic  tests 
the  same  point  of  saturation;  he  fixes  it  at  89  carbon  and 
deduces  from  it  an  unstable  carbide  of  Fe,,4C. 

The  magnetic  maximum  was  found  by  magnet-makers 
by  actual  use  in  large  numbers  of  magnets.  Prof.  J.  "W. 
Langley  found  the  same  maximum  in  a  series  of  careful 
and  delicate  experiments  undertaken  to  determine  the  best 
composition  and  the  best  treatment  for  the  production  of 
permanent  magnets.  Magnetism  is  affected  by  tempera- 
ture, and  it  is  found  that  steel  becomes  non-magnetic  at  or 
about  the  point  of  recalescence.  This  is  important  to  elec- 
tricians, as  it  marks  the  limit  of  temperature  that  is  availa- 
ble to  them.  It  is  of  interest  to  the  scientists,  as  it  is 
another  indication  of  the  importance  of  the  changes  that 


A  MANUAL   FOR  STEEL-USERS.  67 

take  place  at  this  temperature.  Later,  recalescence  will  be 
found  to  be  an  equally  important  point  to  the  steel- worker, 
especially  to  the  temperer 

It  has  been  stated  that  if  a  bar  of  steel  be  heated  to  any 
visible  temperature  and  then  be  cooled  without  disturbance 
there  will  be  a  resulting  grain  or  structure  that  is  due  to 
the  highest  temperature  to  which  the  bar  was  subjected. 
As  a  rule  the  highest  temperature  leaves  a  grain  that 
appears  to  the  eye  to  be  the  largest,  or  coarsest,  whether 
the  microscope  shows  it  to  be  composed  of  larger  crystals 
or  not. 

Let  the  following  squares  represent  the  apparent  sizes  of 
the  grains : 


m  S  LU 


1.  The  natural  bar,  untreated 

2.  Grain  due  to  dark  orange  or  orange  red. 

3.  "        "    "  medium  orange 

4.  «       "    "  bright  orange 
5       «       «    «  dark  lemon 

6.  "       "     "  medium  lemon 

7.  "       "     "  bright  lemon 

8.  "       "     "  very  bright  lemon,  or  creamy. 

These  designations  are  used  because  steel  in  cooling  down, 
or  in  heating  up,  runs  through  a  series  of  yellow  tints,  not 
reds.  It  is  common  to  see  the  expression  "glowing  white  " 
applied  to  steel  that  is  not  even  melted,  when  as  a  matter 
of  fact  melted  wrought  iron  is  not  quite  white.  An  occa- 
sional heat  of  steel  may  be  seen  that  could  fairly  be  called 
white,  and  then  the  melter  knows  that  it  is  altogether  too 
hot,  and  that  he  must  cool  the  steel  or  make  bad  ingots. 


68 

"  Glowing  white,"  like  "cherry  red/'  will  do  for  ordinary 
talk,  but  not  for  accurate  description,  although  "cherry 
red"  conies  nearer  to  describing  the  dying  color  than 
"glowing  white"  conies  to  describing  the  highest  heat. 

An  arc  light  may  be  "glowing  white,"  and  sunlight  is 
"glowing  white,"  and  when  either  light  falls  upon  melted 
steel  it  shows  how  far  the  steel  is  from  being  ''glowing 
white/' 

Referring  to  the  squares:  If  a  bar  that  has  been  heated 
to  No.  8  be  re-heated  to  No.  2  and  be  kept  at  that  color  a 
few  minutes  to  allow  the  steel  to  arrange  itself,  in  other 
words,  to  provide  for  lag,  amVthen  be  cooled,  it  will  be  found 
to  have  grain  No.  2.  Sometimes  in  performing  this  experi- 
ment the  fracture  will  be  interspersed  with  brilliant  spots 
as  if  it  were  set  with  gems;  this  shows  that  not  quite 
enough  time  was  allowed  for  lag.  Another  trial  with  a 
little  more  time  will  bring  it  to  a  complete  No.  2  fracture. 
If  now  it  be  heated  to  No.  4,  or  5,  or  G  in  the  same  way, 
it  will  be  fourfil  to  have  when  cold  the  grain  due  to  No.  4, 
or  5,  or  G  temperature. 

This  may  be  repeated  any  number  of  times,  and  the 
changes  may  be  rung  on  all  of  the  numbers,  until  the  dis- 
integrating effect  of  numerous  heatings  begins  to  destroy 
the  steel.  This  property  of  registering  temperature,  this 
steel  thermometer,  is  of  great  value,  and  it  will  be  referred 
to  frequently. 

EFFECTS   OF    MECHANICAL   WORK. 

When  an  ingot  is  heated  and  then  hammered,  rolled,  or 
pressed  hot,  its  density  will  be  increased,  as  well  as  its 
strength  when  cold  under  all  strains. 

If  it  be  hammered  carefully,  with  heavy  blows  at  first, 


A    MANUAL    FOR   STEEL-USERS.  69 

and  with  lighter  aud  quicker  blows  at  the  last,  the  grain 
will  become  very  close  and  fine;  it  is  called  "hammer- 
refined." 

When  down  to  the  so-called  cherry  red,  orange  red, 
great  care  is  needed,  and  when  black  begins  to  show 
through  the  red  much  caution  must  be  used;  any  heavy 
blows  will  crush  the  grain  and  produce  the  dark  or  black 
color  mentioned  before. 

Fine-tool  makers  attach  great  importance  to  this  hammer- 
refining;  some  of  the  most  expert  will  not  have  a  rolled  bar 
if  a  well-hammered  one  can  be  had.  At  first  thought  this 
would  seem  to  be  a  mere  notion,  but  the  testimony  in  favor 
of  hammering  is  so  universal  among  those  who  know  their 
business  that  it  would  seem  as  if  it  must  be  based  upon 
some  reason.  If  it  have  any  scientific  basis  of  fact,  it  is 
that  the  shocks  or  vibrations  of  the  hammer  keep  the 
carbon  in  more  intimate  union  with  the  iron,  whether  it  be 
combination  or  solution,  than  either  rolling  or  pressing 
will  do.  After  considering  the  phenomena  of  hardening, 
tempering,  annealing,  etc.,  it  may  be  concluded  that  there 
is  something  in  this.  It  is  easy  to  laugh  at  and  to  deride 
shop  prejudices,  and  there  are  enough  of  them  that  deserve 
ridicule;  again,  there  are  some  that  will  not  down,  and  they 
compel  the  scientist  to  hunt  for  explanations.  But  after 
all,  ridicule  is  dangerous;  it  is  possible  that  a  careful  com- 
parison of  some  of  the  laws  laid  down  by  the  highest 
scientists  would  tend  to  excite  the  risibles.  If  the  hand- 
worker sometimes  flounders  in  the  mud,  the  scientist  is 
sometimes  enveloped  and  groping  in  mist. 

Hot-rolling  produces  results  similar  to  those  of  hot-ham- 
mering; it  makes  the  grain  finer,  increases  density,  and 
adds  to  the  strength. 


70  -STEEL: 

The  same  precautions  are  needed  in  rolling  as  in  ham- 
mering. Heavy  passes  with  rapid  reduction  may  be  used  to 
advantage  while  the  steel  is  hot  and  thoroughly  plastic;  :is 
the  heat  falls  the  passes  should  be  lighter  to  avoid  crush- 
ing the  grain. 

Overrolling,  like  too  much  hammering,  may  be  more 
injurious  than  too  little  work;  a  coarse,  irregular  structure 
due  to  too  little  work  may  be  rectified  and  made  fine  and 
even  by  annealing,  while  if  the  grain  be  crushed  by  over- 
work the  damage  cannot  be  cured  by  annealing;  the* an- 
nealed grain  may  appear  to  be  all  right,  but  on  testing,  the 
strength  will  be  found  impaired. 

By  care  and  light  passes  steel  may  be  rolled  safely  down 
to  a  black  heat  and  be  made  elastic  and  springy.  It  is 
common  to  roll  spring-steel  in  this  way  so  that  it  may  be 
formed  into  a  spring  and  have  all  of  the  properties  of  a 
tempered  spring  without  going  through  the  onerations  of 
hardening  and  tempering.  This  is  often  desirable  for 
spring-makers,  as  it  saves  them  considerable  expense  ;  but 
it  is  hazardous  work,  because  it  is  so  difficult  to  heat  every 
piece  exactly  to  the  same  temperature,  and  secure  every 
time  the  same  number  of  passes  and  the  same  pressure  in 
each.  The  best  roller  will  get  some  pieces  too  hard  and 
brittle,  and  some  too  soft  and  ductile.  A  careful  steel- 
maker will  shun  such  work. 

Cold-hammering,  cold-rolling,  and  cold-drawing  reduce 
specific  gravity  and  increase  tensile,  transverse,  compres- 
sive,  and  torsional  strength.  They  increase  hardness  and 
brittleness,  reducing  ductility.  The  hardness  due  to  cold- 
working  is  different  from  that  due  to  hot-work  or  quench- 
ing ;  the  latter  operations  produce  great  elasticity  as  well 
as  hardness. 


A  MANUAL  FOR  STEEL-USERS.  71 

The  hardness  due  to  cold-working  might  be  described  as 
harshness;  the  steel  is  not  truly  springy;  of  course  it  will 
bend  farther  without  permanent  set  than  an  annealed 
piece,  but  it  never  lias  the  true  spring  elasticity.  If  it  be 
worked  far  enough  to  be  really  springy,  it  will  bear  the 
same  relation  to  a  hot-worked  spring  that  a  piece  of  cross- 
grained,  brashy  oak  bears  to  a  piece  of  well-seasoned, 
straight-grained  hickory. 

The  hammering  of  round  sections  between  flat  dies  tends 
to  burst  the  bars  in  the  centre;  great  care  must  be  used 
to  avoid  this,  and  the  most  skilful  and  careful  hammermen 
will  often  turn  out  bursted  bars.  The  bursts  do  not  show 
on  the  surface;  the  bars  are  true  to  size,  round,  smooth,  and 
sound  on  the  outside.  The  safest  plan  is  to  hammer  in  a 
V-die,  or  in  rounded  swedges. 

Radial  rolling  will  produce  the  same  results,  and  it  is  on 
this  principle  that  the  celebrated  Mansmann  tubes  are 
made.  The  explanation  seems  to  be  simple,  as  the  follow- 
ing exaggerated  sketches  will  show: 


No.  1  has  been  struck;  it  is  then  turned  up  to  position 
No.  2  and  knocked  into  shape  No.  3.  The  rapid  hammer- 
ing of  a  bar,  turning  it  a  little  at  a  time,  must  burst  it  if 
the  blows  are  heavy  enough  to  deform  the  whole  section. 
Heavy  radial  rolling  produces  the  same  results. 

The  concluding  pages  of  this  chapter  will  be  devoted  to 
a  few  examples  showing  by  tests  the  effects  of  heat  and 
work  upon  specific  gravity,  tensile  strength,  elasticity,  and 


STEEL: 


ductility;  they  are  not  to  be  taken  as  fixing  exact  limits  in 
any  case;  they  are  given  merely  to  illustrate  the  truth  of 
the  general  properties  stated,  and  to  show  the  wide  ranges 
of  strength  that  are  attainable  by  varying  carbon  and 

work. 

TABLE  I. 


Crucible 

Ingot  Numbers. 

Steel. 

1 

2 

3 

4 

5 

6         7 

8 

9     1    10    |    11         12 

C  .rbon.... 

Silicon. 

.30-1 

.019 

.490 
.034 

.529    .649 

.04:J.     .039 

.801 
.0'.'9 

.8411    .867 
.039!    .0.77 

.871     .9551.005 
.053:    .059     .OS* 

1.058    1  o;9 
.120      .039 

Phosphorus  . 
Sulphur  

.047 

.018 

005 
.010 

.047 
.018 

.030 

.012 

.035 
.016 

.024 
.010 

.0141   .024 
.0181   .012 

.070    .034 
.016]    .012 

.064      .('44 

.006      .001 

Sp.gr  ingots. 

7.855 

7.831)7.841     .8','9 

7.838  7.824  7.819J7.818 

7.8137.8077.803    7.805 

Sp.  gr.   bars, 

burned,  1  .  . 

7.818 

.791 

7.789  ... 

.752     ....17.744 

....     7  fiflO 

3 

7.  814     .811 

7.8'J3'    .  88C 

7.7841  755 

7   THi)                !       7M-t 

17.749 

'    -      ^''9 

4.  . 

7  Sl)S!      '            T7M 

7  789 

7  *')8 

7.S31     .806 

.... 

7.812 

.790 

7.812 

7.  Ml 

cold,  6.... 

7.84-1  7.824 

.... 

7.H-.-9 

.  S25 

7.826 

7.K-.T, 

Diflf.  6-1  

.025    .034 

.040 

.073 

.     .082 

Mean     diflf  .  1 

071 

".'.". 

! 

of  carbon  f 

The  twelve  ingots  treated  here  were  first  selected  by  oc- 
ular inspection  for  carbons;  the  carbons  were  then  de- 
termined by  combustion  analyses. 

It  will  be  seen  that  the  inspection  was  correct,  and  that 
the  mean  difference  in  carbon  between  consecutive  num- 
bers is  .007.  Between  Xos.  7  and  8  there  is  a  difference  of 
only  .004  ;  when  the  analyst  discovered  this,  he  asked  for  a 
reiuspectiou,  not  giving  any  reason  for  his  request.  The 
inspectors  made  new  fractures,  examined  the  ingots  care- 
fully in  good  light,  and  reported  that  they  erred  the  first 
time,  that  both  ingots  belonged  in  the  same  temper  num- 
ber, but  that  if  there  were  any  difference  Xo.  8  was  the 
harder.  It  is  not  claimed  that  a  difference  of  .004  is 
really  observable. 

The  contents  of  silicon,  phosphorus,  and  sulphur  show 
clearly  that  the  controlling  element  is  carbon,  This  ex- 


A   MANUAL   FOK   STEEL-USERS.  73 

periment  has  been  repeated  a  number  of  times,  and  always 
with  the  same  result,  showing  that  there  is  no  uncertainty 
in  this  method  of  separating  tempers. 

Parts  of  these  ingots  were  reduced  to  f-inch  round  bars. 
The  specific  gravities  of  the  ingots  were  taken,  showing 
generally  a  reduction  of  sp.  gr.  for  an  increase  of  carbon- 
No.  3  and  5  are  anomalous;  an  explanation  of  this  could 
doubtless  have  been  found  if  a  careful  investigation  had 
been  made,  but  there  was  no  re-examination. 

The  sp.  gr.  No.  6  are  of  the  f-inch  bars  as  they  came 
from  the  rolls;  they  are  all  heavier  than  the  ingots  except 
No.  4,  and  they  are  of  nearly  uniform  sp.  gr.;  this  is  due 
doubtless  to  the  fact  that  the  higher  carbon  steels  are  so 
much  harder  than  the  low-carbon  steels  that  it  required 
much  more  work  to  reduce  them  to  the  bars,  and  as  hot- 
working  increases  density,  the  densities  of  the  higher  car- 
bons were  increased  more  than  those  of  the  lower. 

The  bars  were  nicked  six  times  at  intervals  of  about  f 
inch  and  then  heated  so  that  the  ends  were  scintillating, 
ready  to  pass  into  the  granular  condition,  and  the  heat  was 
so  regulated  as  to  have  each  piece  less  hot  than  the  piece 
next  nearer  to  the  end,  the  last  piece,  No.  G,  being  black 
and  as  nearly  cold  as  possible. 

It  is  manifest  that  this  operation  is  subject  to  the  error 
of  accidentally  getting  No.  2,  for  instance,  hotter  than  No. 
1,  and  so  on,  so  that  perfect  regularity  is  not  to  be  ex- 
pected; to  obtain  a  true  rule  of  expansion  it  would  be 
necessary  to  make  hundreds  of  such  experiments  and  use 
the  mean  of  all. 

It  will  be  noticed  that  No.  4  is  abnormal  in  the  ingot 
series,  and  that  the  No.  G  piece  of  No.  4  is  abnormal  in  be- 
ing lighter  than  the  ingot;  probably  this  No,  G  of  No,  4. 


74 


6TEEL: 


was  hot  when  it  was  intended  to  be  cold.  Also  No.  2  of 
ingot  No.  3  is  lighter  than  its  No.  1,  showing  another 
irregularity  in  heating. 

Taking  the  whole  list  of  No.  1  pieces,  they  are  all  lighter 
than  their  respective  No.  6  pieces;  the  differences  of  sp. 
gr.  G-l  are  progressive,  being  only  .025  for  the  No.  3  ingot 
and  .135  for  the  No.  12  ingot.  This  shows  clearly  that  ex- 
pansion due  to  a  given  difference  in  temperature  is  much 
greater  in  high  steel  than  in  low  steel. 

This  clears  away  the  mystery  of  the  so-called  treachery  of 
high  steel,  its  tendency  to  crack  when  hardened.  There 
is  no  treachery  about  it;  it  is  very  sensitive  to  temperature? 
and  it  must  be  treated  accordingly. 

A  few  examples  will  now  be  given  to  show  the  changes 
of  tensile  strength,  ductility,  etc.,  that  may  be  had  by 
differences  of  carbon,  and  by  differences  of  treatment,  an- 
nealing, hardening,  and  tempering. 


Cruci- 

Cruci- 

Cruci-    1  C-W 

Character  of 
Steel. 

(jru- 
O.  H.'cible 
Sheet 

0.  H. 

0.  H. 

0.  H. 

bleEye- 
bar. 

bleEye- 
2"  x  1". 

We  Eye-    ^;,e 

Carbon  ......  -] 

.09  to 
.12 

.435 

.50 

.60 

.70 

.96 

TaT 

1.40       !   1.15 

Silicon  

.008 

.014 

.005 

.  1  56 

<   O'J 

Phosphorus..  . 

.007 

.050 

.016 

.008 

'      <   U'* 

Sulphur  

.026 

.0.'3 

.028 

.015 

I!!!.'."..!!  trace 

Manganese   .. 

.055 

.204 

.325 

.24 

<.30 

Tensile  str'gth. 

Ibs.  per  sq.in. 
Elastic  limit... 
Elongation.  ..  -J 

46800 
3H1IOO 
in  2 
in.  41* 

73142 

in  1 
in.  42* 

84220 
62560 
25* 

I08SOO 
71500 
14.  5S 

117400 
69980 
11.5* 

124800 
65000 
4.75* 

1007*3 
85078 
.5* 

117710     141500 
69850       924-JO 
7.28  at         v* 
2.85  in  2^i     " 

Reduction  of  ) 
area  ~i 

75.85* 

63.3* 

29.9155 

13.55* 

8.59*1    

13.03*       2.42* 

( 

f 

broke 

1 

Fracture  -j 

silky 
J^cup 

in  neck 
slight, 
flaw. 

broke 
in  head 
close 

(broke 

'"  \       fine 

grain 

grip 

L 

I    grain 

O.  H.  is  the  abbreviation  for  open  hearth. 

Secoucl  column  is  mean  of  24  analyses  aucl  34  tests  o£  boiler-sheets. 


A  MANUAL   FOR  STEEL-USERS. 
TABLE  III. 


Cold-drawn  Wire,  ^  inch  Diam. 

Tensile 
Strength, 
Ibs.  per 
sq.  in. 

Elastic 
Limit, 
Ibs.  per 
sq.  in. 

93,400 
114.700 
68,110 

152,800 

Elonf 

In  3 
in. 

.06 
.18 
.90 

.25 

Cation. 

Per 
cent. 

2.00 
6.00 
10.00 

8.33 

Reduc- 
tion of 
Area, 
per  ct. 

2.  42 
12.45 
11.  69 

19.7 

141.500 
138.400 
98,410 

248,700 

Same  bar  drawn  black  

"    hardened  and   then   drawn 
black  . 

Analysis  of  this  bar  is  given  in  Table  II  in  the  last 
column. 

A  test  of  4-inch  wire  to  show  effect  of  cold-drawing, 
tempering,  annealing,  and  hardening  and  tempering. 
Four  pieces  were  cut  from  the  same  bar.  It  is  probable 
that  the  first  piece  would  have  given  a  little  higher  tensile 
if  it  had  not  broken  in  the  grip;  it  was  clamped  too  tight. 
The  second  piece  was  heated  until  it  passed  through  all  of 
the  temper  colors  and  turned  black,  technically  called 
"drawing  black/'  or  drawing  out  all  of  the  temper.  It  is 
not  quite  annealing;  the  idea  was  to  find  the  effect  of 
temper-drawing  upon  a  cold-hardened  drawn  wire. 

The  effect  of  this  operation  was  to  lower  the  ultimate 
and  raise  the  elastic  strength,  increasing  also  the  ductility. 

The  third  piece  was  heated  carefully  to  the  recalescence- 
point,  and  cooled  slowly,  thus  annealing  it  completely,  and 
giving  the  normal  strength  of  a  bar  of  this  composition. 

The  fourth  piece  was  heated  to  recalescencc  and 
quenched,  hardening  and  refining  it  thoroughly;  it  was 
then  tempered  through  all  of  the  colors  until  it  turned 
black;  the  result  shows  the  enormous  potencies  there  are 
in  the  hardening  and  tempering  operations. 

The  cases  given  in  Table  II  were  selected  indiscrimi- 
nately, so  as  to  show  better  the  effect  of  carbon,  as  we  here 


have  tests  of  ordinary  test-bars,  boiler-sheet,  small  eye- 
bars,  and  drawn  wire. 

The  96-carbon  eye-bar  and  the  115-carbon  4-inch  wire 
are  the  nearest  to  the  100-carbon  saturation  limit  men- 
tioned before,  and  they  show  the  highest  strength.  The 
96-carbon  eye-bar  had  a  slight  flaw  in  the  fracture,  which 
doubtless  caused  it  to  break  below  its  real  strength. 

The  135-carbon  eye-bar  broke  in  the  head  in  a  Avay  to 
indicate  that  there  was  some  local  strain  there,  due  to 
forging. 

These  examples  are  not  given  as  establishing  any  gen- 
eral law;  they  are  illustrations  of  Avhat  all  experience 
shows  to  be  the  fact,  that  the  strength  of  steel  is  affected 
profoundly  by  the  quantity  of  carbon  present,  and  also 
by  heat  and  by  mechanical  work.  From  40,800  Ibs.  to 
248,700  Ibs.  tensile  strength  per  square  inch  is  an  enor- 
mous range,  and  these  figures  probably  represent  pretty 
closely  the  ultimate  limits  at  present  attainable. 

An  inspection  of  the  analyses  makes  it  clear  that  the 
other  elements  present  in  addition  to  carbon  were  not  there 
in  sufficient  quantity  or  variety  to  have  had  much  effect 
upon  the  results. 


A  MANUAL   FOR   STEEL-USERS.  77 


VL 

HEATING  FOR  FORGING;  FOR  HARDENING; 
FOR  WELDING. 

BURNING,   OVERHEATING,  RESTORING. 

FROM  what  lias  been  said  already  about  the  effects  of 
heat  it  follows  without  further  argument  that  heating  is 
one  of  the  most  important,  or  perhaps  more  properly  the 
most  important  of  all,  of  the  operations  to  which  steel  has 
to  be  subjected. 

The  first  and  vital  thing  to  be  borne  in  mind  is  that  all 
"heating  should  be  uniform  throughout  the  mass.  It  has 
been  shown  that  heat  affects  the  grain,  the  structure,  as 
surely  as  it  moves  the  mercury-column,  and  such  being 
the  case  it  is  plain  that  as  perfect  uniformity  as  it  is  pos- 
sible to  attain  is  the  first  essential  for  all  heating,  no  matter 
what  the  ultimate  object  may  be. 

In  heating  for  forging  the  limit  lies  between  the  point 
of  recalescence,  the  beginning  of  true  plasticity,  and  the 
granular  condition,  the  end  of  plasticity;  these  tempera- 
tures lie  between  dark  or  medium  orange  for  all  steels  and 
medium  or  light  lemon  on  the  upper  limit,  depending  on 
the  carbon  content,  or  lower  if  it  be  an  alloy  steel. 

If  there  is  much  work  to  be  done  upon  a  piece  of  steel, 
it  is  well  to  heat  at  first  to  as  high  a  temperature  as  is  safe, 
and  then  to  forge  or  work  heavily  at  the  higher  heat, 


78  STEEL: 

reducing  the  blows  or  passes  as  the  piece  is  reduced  and 
the  temperature  falls.  Although  this  high  heating  will 
raise  the  grain  of  the  steel,  the  heavy  working  will  bring  it 
back  to  a  fine,  compact  structure. 

If  little  work  is  to  be  done,  then  it  is  better  to  heat  as 
low  as  may  be  safe,  and  allow  the  work  to  be  done  without 
letting  the  heat  down  below  orange  red,  so  that  the  steel 
may  not  be  crushed  in  the  grain. 

Below  orange  red,  the  so-called  "  dark  cherry,"  steel 
should  not  be  forged,  except  that  in  forging  for  line  tools 
it  is  well  to  give  many  light  and  rapid  blows  until  black 
begins  to  show  in  order  to  hammer-refine  it;  this  must 
be  done  with  extreme  care  so  as  not  to  crush  the  steel  and 
cause  cracking  in  the  subsequent  hardening,  or  crumbling 
in  the  hardened  tool. 

HEATIXG   FOR   HARDEXIXG. 

When  a  piece  of  steel  is  to  be  hardened  by  quenching  in 
water  or  any  quick-cooling  medium,  it  should  be  heated 
with  great  c;ire  to  the  exact  temperature  to  produce  the 
required  hardness. 

After  forging,  no  piece  of  steel  should  be  quenched  with- 
out first  being  heated  uniformly  to  the  proper  temperature. 
Ede  in  his  book  recommends  quenching  immediately  after 
forging  in  some  cases.  The  so-called  Harvey  patent  recom- 
mends cooling  from  a  high  heat  down  to  the  required  heat 
and  then  quenching. 

Both  practices  are  bad.     In  the  Ede  case  this  is  believed 

to  be  the  only  bad  piece  of  advice  in  his  very  valuable  book 

—  in  every  other  respect  the  most  practical  and  useful  book 

upon  the  manipulation  of  steel  known  to  the  author. 

The  reason  for  objecting  to  the  quenching  after  forging 


A    MANUAL   FOR  STEEL-USERS.  79 

without  re-heuting  is  that  forging  always  sets  up  uneven 
strains  in  the  mass;  the  flow  is  easier  from  the  sides  than 
from  the  middle  of  the  piece,  and  therefore  the  amount  of 
work  done  upon  one  part  is  greater  than  upon  another;  also 
it  is  impossible  to  hammer  or  press  a  piece  of  steel  with 
exact  uniformity  throughout,  so  that  it  follows  that  after 
forging  there  is  never  exact  uniformity  of  texture  or  temper- 
ature, and  such  uniformity  is  the  one  essential  thing  to  in- 
sure good  and  even  hardening. 

The  practice  of  allowing  a  highly  heated  piece  to  cool 
down  to  a  given  color  and  then  quenching  is  objectionable, 
because  it  produces  a  coarse  and  brittle  grain  due  to  the 
higher  heat.  « 

Referring  to  the  illustration  on  page  67  of  the  squares 
representing  grains  due  to  different  temperatures:  Assume 
that  square  No.  3  represents  the  heat  at  which  quenching 
is  to  take  place,  and  No.  G  is  the  heat  to  which  the  piece 
has  been  subjected;  then  the  piece  when  it  has  cooled  to 
No.  3  will  not  have  the  grain  due  to  Xo.  3  heat:  it  will 
have  a  larger,  coarser  grain  that  formed  as  the  piece  cooled 
from  No.  G.  If  now  it  be  quenched,  it  will  have  only  the 
hardness  due  to  No.  3,  with  a  much  coarser  and  more 
brittle  grain  than  No.  3  heat  should  give.  The  way  to 
manage  such  a  case  is  to  let  the  piece  cool  completely  and 
assume  the  No.  6  grain;  then  re-heat  carefully  to  exactly 
No.  3  and  no  hotter;  keep  the  piece  at  that  heat  for  a  few 
minutes,  or  moments,  according  to  its  size,  to  allow  for  lag: 
then  it  will  have  the  finer  grain  due  to  No.  3  heat,  and 
when  quenched  it  will  be  as  hard  as  under  the  other 
method,  and  it  will  be  much  finer  and  stronger. 

The  same  rule  applies  to  any  two  temperatures. 

As  an  expression  of  exactness  as  to  evenness  of  heat,  it 


80  STEEL: 

may  be  said  that  the  piece  should  be  as  uniform  in  color  as 
if  it  had  been  dipped  into  a  pot  of  paint.  When  such  uni- 
formity is  attained,  a  break  from  quenching  is  rare,  unless 
the  piece  has  been  shamefully  overheated  so  that  the  strains 
of  quenching  are  greater  than  the  tenacity  of  the  steel. 

HEATING    FOR   WELDING. 

When  an  ingot  is  to  be  forged  or  rolled,  it  is  well  to  take 
the  highest  heat  possible — that  immediately  below  the  heat 
of  granulation.  Such  a  heat  may  be  taken  safely  by  keep- 
ing the  steel  covered  with  a  surface  flux  to  protect  it  from 
the  flame.  Ordinary  red  clay,  dried  and  powdered,  is  an 
excellent  flux  for  the  purpose,  and  the  cheapest  known. 
Melted  and  powdered  borax  is  the  best  of  known  fluxes, 
but  it  is  so  expensive  that,  as  a  rule,  it  is  used  only  on  the 
finest  tool-steel,  or  on  some  of  the  alloy  steels  where  the 
highest  heat  possible  is  not  above  a  bright  orange  color,  or 
hardly  so  high. 

A  good  flux,  intermediate  in  cost  between  common  red 
clay  and  powdered  borax,  is  an  earth  or  mineral  barite,  or 
heavy  spar.  This  material  fuses  more  readily  than  red 
clay  and  not  quite  so  easily  as  borax.  It  forms  a  good 
protective  covering  on  the  steel,  and  it  is  nearly  or  quite 
as  efficient  as  borax. 

The  object  in  heating  so  high  is  to  make  the  steel  as  soft 
and  plastic  as  it  may  be,  so  that  the  subsequent  working 
will  close  up  all  porosity  as  far  as  possible.  Nearly  all 
ingots  have  in  them  a  greater  or  less  number  of  cavities, 
commonly  called  blow-holes,  that  are  caused  by  the  separa- 
tion of  occluded  gases  during  cooling.  If  such  porosities 
are  not  oxidized  on  the  surface  they  will  disappear  under 
heavy  working  at  a  high  heat.  It  is  probable  that  under 


A   MANUAL   FOR   STEEL-USERS.  81 

the  compression  of  the  work  the  gases  are  redisserninated 
in  the  mass  and  the  walls  of  the  cavities  are  reunited.  If 
there  be  the  slightest  oxidation  of  the  surface  of  a  cavity 
the  walls  will  not  reunite:  there  will  be  left  in  the  mass  a 
little  flat  film  of  oxide  which  will  prevent  the  union. 

Ill  mild  steels  used  for  machinery  or  structural  purposes 
these  little  films  may  do  no  harm,  the  factor  of  safety 
being  sufficient  to  more  than  cover  any  weakening  effect. 
In  tool-steel  that  is  to  be  hardened  such  little  films  are 
almost  certain  to  cause  fracture.  Dies  as  large  as  twelve 
inches  square  and  six  to  eight  inches  thick,  having  been 
heated  and  quenched  with  the  greatest  care,  have  split 
fairly  in  two,  and  have  revealed  in  the  fracture  a  little  film 
no  larger  than  half  an  inch  in  diameter  and  of  inappreci- 
able thickness.  At  the  same  time  the  perfectly  uniform 
grain  and  hardness  showed  that  the  highest  skill  had  been 
used.  This  is  only  one  illustration  of  the  fuct  that  every 
break  in  the  continuity  of  the  grain  in  steel  forms  a  start- 
ing-point for  fracture  under  heavy  stress. 

From  what  has  been  said  it  is  plain  that  to  weld  two 
pieces  of  steel  together  is  a  difficult  matter;  still  it  can  be 
done  if  great  care  be  used.  In  genenil  it  is  better  to  avoid 
such  welding  except  in  cases  of  necessity.  The  welding 
of  steel  tubing,  and  the  electric  welding  of  rails,  frogs, 
switches,  etc.,  is  done  on  a  large  scale  and  satisfactorily,  so 
that  it  will  not  do  to  say  that  steel  cannot  be  welded.  It 
can  be  welded  or  pasted  together,  and  it  is  a  good  opera- 
tion to  avoid  in  all  high  steel.  In  case  steel  is  to  be  hard- 
ened a  weld  will  reveal  itself  almost  certainly. 


88  STEEL: 


BURNING    IX    HEATING. 

When  a  piece  of  steel  breaks  and  shows  a  coarse,  fiery 
fracture,  it  is  common  to  say  that  it  is  burned.  This  is 
not  necessarily  the  case.  There  are  several  degrees  in  the 
effects  of  heat.  The  first  is  the  raising  of  the  grain;  the 
second,  in  high  steel,  is  the  decarbonizing  or  burning  out 
of  carbon  from  the  surface  in,  the  depth  of  the  decarboniz- 
ing depending  upon  time  and  temperature;  the  third  is 
oxidizing,  or  actual  burning  in  the  common  acceptance  of 
the  term. 

All  of  these  operations  go  on  to  a  slight  extent  every 
time  a  piece  of  steel  is  heated,  but  when  the  heating  is 
done  carefully  there  is  only  a  small  film  of  steel  that  is  de- 
carbonized and  oxidized,  and  this  film  flies  off  when  the 
piece  is  quenched  for  hardening.  When  the  steel  is  forged 
or  rolled  this  skin  will  be  united  firmly  to  the  steel,  and  it 
will  be  thinner  or  thicker,  according  to  the  number  of 
heatings  and  the  time  of  exposure  to  the  fire.  In  tool- 
making  this  skin  must  always  be  removed.  Many  an  ex- 
pensive tool  is  made  perfectly  worthless  by  not  having  this 
skin  all  removed,  owing  usually  to  mistaken  economy. 
The  steel  is  expensive,  and  the  tool-maker  does  not  wish  to 
cut  it  up  into  worthless  chips. 

When  a  tool  costing,  say,  twenty-five  dollars  is  made 
useless  by  failure  to  cut  away  twenty-five  cents'  worth  of 
useless  skin,  the  economy  of  such  an  operation  requires  no 
discussion.  It  is  impossible  to  forge  a  piece  of  steel  with- 
out producing  such  a  skin,  and  it  is  well  known  that  de- 
carbonized iron  will  not  harden. 

Ordinarily  a  cut  of  ^  of  an  inch  should  remove  such  a 
skin  on  straight  rolled  or  hammered  bars.  In  the  case  of 


A  MANUAL   FOR  STEEL-USERS.  S3 

a  shaped  forging  where  many  re-heatings  have  been  re- 
quired the  forgemau  will  have  done  good  work  if  the  cut- 
ting away  of  £  of  an  inch  will  present  a  good  surface: 
tool-makers  should  consider  this  and  allow  for  it.  On  the 
other  hand,  if  a  tool-maker  finds  that  the  removal  of  £  of 
an  inch  from  a  bar,  or  i  of  an  inch  from  a  forging  will  not 
yield  him  a  good,  hard  surface,  he  should  hold  the  steel- 
maker responsible  for  bad  work. 

Actual  burning  reveals  itself  in  rough  tears,  and  cracks 
at  the  surface  and  corners  of  the  piece.  Such  a  piece 
should  go  to  the  scrap  heap. 

Overheated  steel  of  coarse,  fiery  grain  has  been  injured, 
and  not  necessarily  destroyed.  Such  a  piece  may  be  re- 
stored to  any  fineness  of  grain  by  heating  to  the  right 
temperature — medium  orange  for  the  best  grain — keeping 
it  at  that  heat  for,  say,  one  minute  for  a  little  piece,  and 
five  to  ten  or  fifteen  minutes  for  a  large  piece.  The  heat 
should  penetrate  the  whole  mass,  and  it  should  not  be 
allowed  to  run  above  the  given  color  in  any  part,  not 
even  for  a  moment.  It  should  then  be  allowed  to  cool  in  a 
dry  place,  without  disturbance.  The  grain  will  now  be 
fine  and  uniform,  and  the  steel  may  be  worked  in  the 
ordinary  way. 

This  simple  operation  is  all  that  is  necessary  to  restore 
to  a  fine  grain  any  piece  of  steel  that  has  been  overheated, 
provided  that  the  piece  has  not  been  actually  burned  nor 
ruptured. 


34  STEEL: 


VII. 

ANNEALING. 

IT  has  been  shown  that  the  grain  or  structure  of  steel  is 
profoundly  affected  by  heat,  so  that  airy  difference  of  heat- 
color  that  is  visible  to  the  naked  eye  will  cause  a  difference 
of  grain  that  is  also  visible  to  the  naked  eye. 

Specific-gravity  tests  and  delicate  magnetic  tests  have 
proved  that  for  every  variation  in  grain  there  is  a  differ- 
ence of  specific  gravity,  which  means,  of  course,  a  difference 
in  volume;  from  this  it  is  clear  that  it'  in  any  one  piece  of 
steel  there  exists  a  variety  of  grain  due  to  uneven  heating, 
there  must  necessarily  be  in  the  mass  internal  destructive 
strains.  These  strains  become  manifest  when  a  piece  of 
unevenly  heated  steel  cracks  in  hardening;  in  this  case  the 
strains  are  greater  than  the  tenacity  of  the  steel. 

It  is  well  known,  also,  that  all  working  of  steel,  such  as 
forging  or  rolling,  has  a  hardening  effect,  so  that  ordinary 
bars  or  forgings  cannot  be  machined  readily  in  the  condi- 
tion in  which  they  are  left  by  these  operations. 

If  there  were  no  remedy  for  these  conditions  of  internal 
stress  and  initial  hardness,  the  general  use  of  steel  would 
be  very  difficult,  and  its  application  would  be  limited 
seriously. 

Fortunately,  there  are  three  properties  of  steel  which 
furnish  an  easy  and  efficient  remedy. 


A   MANUAL   FOR   STEEL-USERS.  85 

First,  the  fact  that  steel  will  assume  by  mere  heating  a 
grain  or  structure  due  to  any  temperature,  no  matter  what 
its  previous  structure  may  have  been,  makes  it  a  simple 
matter  to  remove  practically  all  irregularities  of  grain  and 
stress,  by  heating  the  mass  to  a  perfectly  uniform  color  and 
allowing  it  to  cool  uniformly. 

Second,  as  heating  is  a  softening  process  always,  the 
mere  heating  of  any  piece  of  steel  will  soften  it,  and  the 
amount  of  this  softness  that  can  be  retained  when  the 
piece  is  cold  is  a  direct  function  of  the  length  of  time  of 
cooling,  so  that  by  sufficiently  slow  cooling  any  steel  can 
be  left  reasonably  soft. 

This  does  not  apply  to  Hadfield's  manganese  steel,  which 
cannot  be  made  soft  when  cold  by  any  of  the  known 
processes  of  annealing. 

Third,  by  reference  to  the  specific-gravity  table  No.  I, 
Chap.  V,  it  will  be  seen  that  the  change  in  volume  due  to 
differences  of  temperature  is  much  less  in  mild  steel  than 
in  high  steel.  This  fact  does  not  rest  upon  the  evidence  of 
this  table  alone;  it  is  a  fact  of  common  knowledge  to  all 
steel-makers  that  mild  steel  is  much  more  inert  than  high 
steel;  therefore  differences  of  heat  and  working  that  pro- 
duce serious  results  in  high  steel  are  hardly  appreciable  in 
mild  steel.  As  a  rule  all  structural  steels  are  comparatively 
mild,  therefore  they  are  generally  in  a  fit  condition  for  use 
when  they  leave  the  rolls  or  forge.  In  cases  of  special 
forging,  where  one  part  is  heated  and  another  is  left  cold, 
as  in  the  forging  of  the  heads  of  eye-bars,  it  would  seem  to 
be  wiser  to  anneal  such  pieces  to  remove  the  area  of  strain 
that  must  exist  between  the  unheated  parts  and  those  that 
were  heated  and  forged. 

The   operation   of  removing  strains  and  hardness    by 


86  STEEL ! 

careful,  uniform  heating  and  slow  cooling  is  known  as 
annealing. 

Annealing  should  not  be  confused  with  tempering.  Tem- 
pering is  the  partial  softening  of  hardened  steel,  to  remove 
some  of  the  exceeding  brittleness  of  hardened  steel,  and  so 
to  make  it  strong  and  highly  elastic  while  it  is  still  very 
hard. 

Annealing  is  the  complete  softening  of  a  piece  of  steel; 
that  is  to  say,  as  a  rule,  the  obtaining  of  the  utmost  softness 
that  is  possible;  or  in  any  case  to  have  the  steel  softer  than 
any  tempering  would  leave  it. 

Annealing,  and  tempering  are  frequently  used  synony- 
mously. Such  misuse  of  terms  in  speaking  of  technical 
mutters  leads  to  confusion  of  ideas  and  misunderstandings. 

As  a  rule,  the  best  heat  to  use  for  annealing  is  that 
which  gives  a  medium  orange  color  ;  it  is  a  good  heat  to 
quench  from;  it  is  a  little  above  the  heat  of  recalescence, 
about  655°  Cent.  This  heat  is  that  which  gives  the  finest 
grain  to  steel  when  it  is  hardened,  and  is  known  as  the  re- 
fining heat. 

As  steel  is  thoroughly  plastic  and  soft  at  this  heat,  and 
as  it  yields  the  best  and  strongest  grain  when  cooled  from 
this  heat,  it  is  clear  that  there  is  nothing  to  be  gained  by 
heating  any  higher  for  annealing. 

In  annealing,  the  steel  should  be  brought  up  to  the  right 
color,  medium  orange,  and  left  at  that  heat  until  it  is  hot 
through,  care  being  taken  that  the  heat  does  not  run  any 
higher  in  any  part  of  the  piece.  If  the  corners  or  edges  or 
any  part  be  allowed  to  run  up  to  bright  orange,  or  to 
medium  or  bright  lemon,  as  is  often  done,  then  there  is 
bad  work ;  the  result  will  be  uneven  grain  and  internal 
strains.  ' 


A  MANUAL   FOR  STEEL-USERS.  8? 

When  steel  is  to  be  hardened  afterwards,  there  may  be 
110  harm  in  heating  up  to  an  even  lemon  color ;  but  where 
is  the  use  in  applying  this  excess  of  heat  merely  to  make  a 
coarse  grain,  when  the  lower,  medium  orange  color  will 
give  just  as  good  softness  and  a  much  better  grain  ? 

The  time  necessary  for  good  annealing  depends  upon 
the  size  of  the  piece ;  a  wire  may  be  brought  up  to  the 
right  heat  in  five  minutes  or  less,  and  heated  through  in 
another  minute  ;  then  it  should  be  removed  from  the  fire, 
as  every  additional  moment  of  heating  will  only  injure  the 
steel. 

A  block  six  or  eight  inches  cube  may  require  three  to 
five  hours  to  bring  it  up  to  the  color  and  have  it  heated 
through,  and  sufficient  time  should  be  given ;  but  as  soon 
as  it  is  hot  through  it  should  be  removed  from  the  fire. 

A  six-inch  block  may  be  brought  up  to  a  medium  orange 
color  in  twenty  minutes  or  less  in  a  hot  furnace,  and  then 
if  it  be  kept  in  such  a  furnace  until  it  is  hot  all  through, 
the  surface  and  edges  will  almost  certainly  be  brought  to  a 
bright  lemon  color,  with  bad  results.  To  do  good  anneal- 
ing a  piece  should  never  be  hotter  in  one  part  than  in  an- 
other, and  no  part  should  be  hotter  than  necessary,  usually 
the  medium  orange  color.  Annealing,  then,  is  a  slow  proc- 
ess comparatively,  and  sufficient  time  should  be  allowed. 

There  are  many  ways  of  annealing  steel,  and  generally 
the  plan  used  is  well  adapted  to  the  result  desired  ;  it  is 
necessary,  however,  to  consider  the  end  aimed  at  and  to 
adopt  means  to  accomplish  it,  because  a  plan  that  is  ex- 
cellent in  one  case  may  be  entirely  inefficient  in  another. 

Probably  the  greatest  amount  of  annealing  is  done  in  the 
manufacture  of  wire,  where  many  tons  must  be  annealed 
daily. 


88  STEEL: 

For  annealing  wire  sunken  cylindrical  pits  built  of  fire- 
bricks tire  used  usually;  the  coils  of  wire  are  piled  up  in 
the  cylinders,  which  are  then  covered  tightly,  and  heat  is 
applied  through  flues  surrounding  the  cylinders,  so  that  no 
flame  comes  in  contact  with  the  steel.  For  all  ordinary 
uses  this  method  of  annealing  wire  is  quick,  economical, 
and  satisfactory.  The  wire  comes  out  with  a  heavy  scale 
of  oxide  on  the  surface  ;  this  is  pickled  off  in  hot  acid,  and 
the  steel  should  then  be  washed  in  limewater,  then  in  clean 
water,  and  finally  dried. 

If  it  be  desired  to  make  drill-wire  for  drills,  punches, 
graving-tools,  etc.,  this  plan  will  not  answer,  because  under 
the  removable  scale  there  is  left  a  thin  film  of  decarbonized 
iron  which  cannot  be  pickled  off  without  ruining  the  steel, 
and  which  will  not  harden.  It  is  plain  that  this  soft 
surface  must  be  ruinous  to  steel  intended  for  cutting- 
tools,,  for  it  prevents  the  extreme  edge  from  hardening — 
the  very  place  that  must  be  hard  if  cutting  is  to  be  done. 

Tools  for  drills,  lathe  tools,  reamers,  punches,  etc.,  are 
usually  annealed  in  iron  boxes,  filled  in  the  spaces  between 
the  tools  with  charcoal;  the  box  is  then  looted  and  heated 
in  a  furnace  adapted  to  the  work.  This  is  a  satisfactory 
method  generally,  because  the  tools  are  either  ground  or 
turned  after  annealing,  removing  any  decarbonized  film 
that  may  be  found  ;  the  charcoal  usually  takes  up  all  of 
the  oxygen  and  prevents  the  formation  of  heavy  scale  and 
decarbonized  surfaces,  but  it  does  not  do  so  entirely,  and 
so  for  annealing  drill-wire  this  plan  is  not  satisfactory.  It 
is  a  common  practice  in  annealing  in  this  way  to  continue 
the  heating  for  many  hours,  sometimes  as  many  as  thirty- 
six  hours,  in  the  mistaken  notion  that  long-continued 
heating  produces  greater  softness,  and  some  people  adhere 


A   MANUAL   FOR  STEEL-USERS.  89 

to  this  plan  iu  spite  of  remonstrances,  because  they  find 
that  pieces  so  annealed  will  turn  as  easily  as  soft  cast  iron. 
This  last  statement  is  true;  the  pieces  may  be  turned  in  a 
lathe  or  cut  in  any  way  as  easily  as  soft  cast  iron,  for  the 
reason  that  that  is  exactly  what  they  are  practically. 
When  steel  is  made  properly,  the  carbon  is  nearly  all  in  a 
condition  of  complete  solution;  it  is  in  the  very  best  condi- 
tion to  harden  well  and  to  be  enduring. 

When  steel  is  heated  above  the  recalescence-point  into 
the  plastic  condition,  the  carbon  at  once  begins  to  separate 
out  of  solution  and  into  what  is  known  as  the  graphitic 
condition.  If  it  be  kept  hot  long  enough,  the  carbon  will 
practically  all  take  the  graphitic  form,  and  then  the  steel 
will  not  harden  properly,  and  it  will  not  hold  its  temper. 
To  illustrate :  Let  a  piece  of  90-carbon  steel  be  hardened 
and  drawn  to  a  light  brown  temper  ;  it  will  be  found  to  be 
almost  file  hard,  very  strong,  and  capable  of  holding  a  fine, 
keen  edge  for  a  long  time. 

Next  let  a  part  of  the  same  bar  be  buried  in  charcoal  in 
a  box  and  be  closed  up  air-tight,  then  let  it  be  heated  to  a 
medium  orange,  no  hotter,  and  be  kept  at  that  heat  for 
twelve  hours,  a  common  practice,  and  then  cooled  slowly. 
This  piece  will  be  easily  cut,  and  it  will  harden  very  hard, 
but  when  drawn  to  the  same  light  brown  as  the  other  tool 
a  file  will  cut  it  easily  ;  it  will  not  hold  its  edge,  and  it 
will  not  do  good  work. 

Clearly  in  this  case  time  and  money  have  been  spent 
merely  in  spoiling  good  material.  There  is  nothing  to  be 
gained,  and  there  is  everything  to  be  lost,  in  long-continued 
heating  of  any  piece  of  steel  for  any  purpose.  When  it  is 
hot  enough,  and  hot  through,  get  it  away  from  the  fire  as 
quickly  as  possible. 


90  STEEL: 

This  method  of  box-annealing  is  not  satisfactory  when 
applied  to  drill-wire,  or  to  long  thin  strands  intended  for 
clock-springs,  watch-springs,  etc. 

The  coils  or  strands  do  not  come  out  even  ;  they  will  be 
harder  in  one  part  than  in  another;  they  will  not  take  an 
even  temper.  When  hardened  and  tempered,  some  parts 
will  be  found  to  be  just  right,  and  others  will  have  a  soft 
surface,  or  will  not  hold  a  good  temper.  The  reason  of 
this  seems  to  be  a  want  of  uniformity  in  the  conditions: 
the  charcoal  does  not  take  up  all  of  the  oxygen  before  the 
steel  is  hot  enough  to  be  attacked,  and  so  a  decarbonized 
surface  is  formed  in  some  parts  ;  or  it  may  be  that  some  of 
the  carbon  dioxide  which  is  formed  comes  in  contact  with 
the  surface  of  the«steel  and  takes  another  equivalent  of  car- 
bon from  it.  Whatever  the  reaction  may  be,  the  fact  is 
that  much  soft  surface  is  formed.  This  soft  surface  may 
not  be  more  than  .001  of  an  inch  thick,  but  that  is  enough 
to  ruin  a  watch-spring  or  a  fine  drill. 

Again,  it  seems  to  be  impossible  to  heat  such  boxes  evenly; 
it  is  manifest  that  it  must  take  a  considerable  length  of  time 
to  heat  a  mass  of  charcoal  up  to  the  required  temperature, 
and  if  the  whole  be  not  so  heated  some  of  the  steel  will 
not  be  heated  sufficiently;  this  will  show  itself  in  the  sub- 
sequent drawing  of  the  wire  or  rolling  of  the  strands.  On 
the  other  hand,  if  the  whole  mass  be  brought  up  to  the  re- 
quired heat,  some  of  the  steel  will  have  come  up  to  the 
heat  quickly,  and  will  then  have  been  subjected  to  that 
heat  during  the  balance  of  the  operation,  and  in  this  way 
the  carbon  will  be  thrown  out  of  solution  partly.  This  is 
proven  by  the  fact  that  strands  made  in  this  way  and 
hardened  and  tempered  by  the  continuous  process  will  be 
hard  and  soft  at  regular  intervals,  showing  that  one  side 


A   MANUAL   FOR   STEEL-USERS.  91 

of  the  coil  has  been  subjected  to  too  much  heat.  This 
trouble  is  overcome  by  open  annealing,  which  will  be  de- 
scribed presently. 

When  steel  is  heated  in  an  open  furnace,  there  is  always 
a  scale  of  oxide  formed  on  the  surface;  this  scale,  being 
hard,  and  of  the  nature  of  sand  or  of  sandstone,  grinds 
away  the  edges  of  cutting-tools,  so  that,  although  the  steel 
underneath  may  be  soft  and  in  good  cutting  condition, 
this  gritty  surface  is  very  objectionable.  This  trouble  is 
overcome  by  annealing  in  closed  vessels;  when  charcoal  is 
used,  the  difficulties  just  mentioned  in  connection  with 
wire-  and  strand-annealing  operate  to  some  extent,  al- 
though not  so  seriously,  because  the  steel  is  to  be  ma- 
chined, removing  the  surface. 

The  Jones  method  of  annealing  in  an  atmosphere  of  gas 
is  a  complete  cure  for  these  troubles. 

Jones  uses  ordinary  gas-pipes  or  welded  tubes  of  sizes 
to  suit  the  class  of  work.  One  end  of  the  tube  is  welded 
up  solid;  the  other  end  is  reinforced  by  a  band  upon  which 
a  screw-thread  is  cut;  a  cap  is  made  to  screw  on  this  end 
when  the  tube  is  charged.  A  gas-pipe  of  about  4-inch 
diameter  is  screwed  into  the  solid  end,  and  a  hole  of  T1?-  to 
^-inch  diameter  is  drilled  in  the  cap. 

When  the  tube  is  charged  and  the  cap  is  screwed  on,  a 
hose  connected  with  a  gas-main  is  attached  to  the  piece  of 
gas-pipe  in  the  solid  end  of  the  tube;  the  gas-pipe  is  long 
enough  to  project  out  of  the  end  of  the  furnace  a  foot  or 
so  through  a  slot  made  in  the  end  of  the  furnace  for  that 
purpose. 

The  gas  is  now  turned  on  and  a  flame  is  held  near  the 
hole  in  the  cap  until  the  escaping  gas  ignites;  this  shows 
that  the  air  is  driven  out  and  replaced  by  gas. 


92  STEEL: 

The  pipe  is  now  rolled  into  the  furnace  and  the  door  is 
closed,  the  gas  continuing  to  flow  through  the  pipe.  By 
keeping  the  pipe  down  to  a  proper  annealing-heat  it  is 
manifest  that  the  steel  will  not  be  any  hotter  than  the  pipe. 
By  heating  the  pipe  evenly  by  rolling  it  over  occasionally 
the  steel  will  be  heated  evenly.  A  little  experience  will 
teach  the  operator  how  long  it  takes  to  heat  through  a 
given  size  of  pipe  and  its  contents,,  so  that  he  need  not  ex- 
pose his  steel  to  heat  any  longer  than  necessary. 

There  is  not  a  great  quantity  of  gas  consumed  in  the 
operation,  becnuse  the  expanding  gas  in  the  tube  makes  a 
back  pressure,  the  vent  in  the  cap  being  small.  This  seems 
to  be  the  perfection  of  annealing.  A  tube  containing  a 
bushel  or  more  of  bright,  polished  tacks  will  deliver  them 
all  perfectly  bright  and  as  ductile  as  lead,  showing  that 
there  is  no  oxidation  whatever.  Experiments  with  drill- 
rods,  with  the  use  of  natural  gas,  have  shown  that  they  can 
be  annealed  in  this  way,  leaving  the  surface  perfectly 
bright,  and  thoroughly  hard  when  quenched.  This  Jones 
process  is  patented. 

Although  the  Jones  process  is  so  perfect,  and  necessary 
for  bright  surfaces,  its  detail  is  not  necessary  when  a  tar- 
nished surface  is  not  objectionable. 

The  charcoal  difficulty  can  be  overcome  also.  Let  a 
pipe  be  made  like  a  Jones  pipe  without  a  hole  in  the  cap 
or  a  gas-pipe  in  the  end.  To  charge  it  first  throw  a  hand- 
ful of  resin  into  the  bottom  of  the  pipe,  then  put  in  the 
steel,  then  another  handful  of  resin  near  tiie  open  end,  and 
screw  on  the  cap.  The  cap  is  a  loose  fit.  Now  roll  the 
whole  into  the  furnace:  the  resin  will  be  volatilized  at  once, 
fill  the  pipe  with  carbon  or  hydrocarbon  gases,  and  unite 


A  MANUAL  FOR   STEEL-USERS.  93 

with  the  air  long  before  the  steel  is  hot  enough  to  be 
attacked. 

The  gas  will  cause  an  outward  pressure,  and  may  be 
seen  burning  as  it  leaks  through  the  joint  at  the  cap. 
This  prevents  air  from  coming  in  contact  with  the  steel. 
This  method  is  as  efficient  as  the  Jones  plan  as  far  as  per- 
fect heating  and  easy  management  are  concerned.  It  re- 
duces the  scale  on  the  surfaces  of  the  pieces,  leaving  them 
a  dark  gray  color  and  covered  with  fine  carbon  or  soot. 
For  annealing  blocks  or  bars  it  is  handier  and  cheaper 
than  the  Jones  plan,  but  it  will  not  do  for  polished  sur- 
faces. This  method  is  not  patented. 

OPEN   ANNEALING. 

Open  annealing,  or  annealing  without  boxes  or  pipes,  is 
practised  wherever  there  are  comparatively  few  pieces  to 
anneal  and  where  a  regular  annealing -plant  would  not 
pay,  or  in  a  specially  arranged  annealing-furnace  where 
drill-wire,  clock-spring  steel,  etc.,  are  to  be  annealed. 

For  ordinary  work  a  blacksmith  has  near  his  fire  a  box 
of  dry  lime  or  of  powdered  charcoal.  He  brings  his  piece 
up  to  the  right  heat  and  buries  it  in  the  box,  where  it  may 
cool  slowly.  In  annealing  in  this  way  it  is  well  not  to  use 
blast,  because  it  is  liable  to  force  all  edges  up  to  too  high  a 
heat  and  to  make  a  very  heavy  scale  all  over  the  surface. 
With  a  little  common-sense  and  by  the  use  of  a  little  care 
this  way  of  annealing  is  admirable. 

It  is  a  common  practice  where  there  is  a  furnace  in  use 
in  daytime  and  allowed  to  go  cold  at  night  to  charge  the 
furnace  in  the  evening,  after  the  fire  is  drawn,  with  steel 
to  be  annealed,  close  the  doors  and  damper,  and  leave  the 


94  STEEL: 

whole  until  morning.  The  furnace  does  not  look  too  hot 
when  it  is  closed  up,  but  no  one  knows  how  hot  it  wiH 
make  the  steel  by  radiation:  the  steel  is  almost  always 
made  too  hot,  it  is  kept  hot  too  long,  and  so  converted  into 
cast  iron,  and  there  is  an  excessively  heavy  scale  on  it. 

Many  thousands  of  dollars  worth  of  good  steel  are  ruined 
annually  in  this  way,  and  it  is  in  every  way  about  the  worst 
method  of  annealing  that  was  ever  devised. 

To  anneal  wire  or  thin  strands  in  an  open  furnace  the 
furnace  should  be  built  with  vertical  walls  about  two  feet 
high  and  then  arched  to  a  half  circle.  The  inports  for 
ilame  should  be  vertical  and  open  into  the  furnace  at  the 
top  of  the  vertical  wall;  the  outports  for  the  gases  of  com- 
bustion should  be  vertical  and  at  the  same  level  as  the 
inports  and  on  the  opposite  side  of  the  furnace  from  the 
itiports.  These  outflues  may  be  carried  under  the  floor  of 
the  furnace  to  keep  it  hot. 

The  bottom  of  the  door  should  be  at  the  level  of  the 
ports  to  keep  indraught  air  away  from  the  steel.  The  an- 
nealing-pot is  then  the  whole  size  of  the  furnace — two  feet 
deep — and  closed  all  around. 

The  draught  should  be  regulated  so  that  the  flame  will 
pass  around  the  roof,  or  so  nearly  so  as  to  never  touch  the 
steel,  not  even  in  momentary  eddies. 

In  such  a  furnace  clock-spring  wire  not  more  than  .01 
inch  in  diameter,  or  clock  spring  strands  not  more  than 
.006  to  .008  inch  thick  and  several  hundred  feet  long,  may 
be  annealed  perfectly.  The  steel  is  scaled  of  course,  but 
the  operation  is  so  quick  and  so  complete  that  there  is  no 
decarbonized  surface  under  the  scale. 

This  plan  is  better  than  the  Jones  method  or  any  closed 
method,  because  the  big  boxes  necessary  to  hold  the 


A   MANUAL   FOR  STEEL-USERS.  95 

strands  or  coils  cannot  bu  heated  up  without  in  some  parts 
overheating  the  steel;  all  of  which  is  avoided  in  the  open 
furnace,  because  by  means  of  peep-holes  the  operator  can 
see  what  he  is  about,  and  after  a  little  practice  he  can  an- 
neul  large  quantities  of  steel  uniformly  and  efficiently. 


90  STEEL: 


VIII. 

HARDENING  AND  TEMPERING. 

FOB  nearly  all  structural  and  machinery  purposes  steel 
is  used  in  the  condition  in  which  it  comes  from  the  rolls 
or  the  forge;  in  exceptional  cases  it  is  annealed,  and  in 
some  cases  such  as  for  wire  in  cables  or  for  bearings  in 
machinery,  it  is  hardened  and  tempered. 

For  all  uses  for  tools  steel  must  be  hardened,  or  hard- 
ened and  tempered.  The  operations  of  hardening  and 
tempering,  including  the  necessary  heating,  are  the  most 
important,  the  most  delicate,  and  the  most  difficult  of  all 
of  the  manipulations  to  which  steel  is  subjected;  these 
operations  form  an  art  in  themselves  where  skill,  care, 
good  judgment,  and  experience  are  required  to  produce 
reliable  and  satisfactory  results.  It  is  a  common  idea  that 
all  that  is  necessary  is  to  heat  a  piece  of  steel,  quench  it 
in  water,  brine,  or  some  pet  nostrum,  and  then  warm  it  to 
a  certain  color;  these  are  indeed  the  only  operations  that 
are  necessary,  but  the  way  in  which  they  are  done  are  all- 
important. 

An  experienced  steel-maker  is  often  amazed  at  the  con- 
fidence with  which  an  ignorant  person  will  put  a  valuable 
tool  in  the  fire,  rush  the  heat  up  to  some  bright  color,  or 
half  a  dozen  colors  at  once,  and  souse  it  into  the  cooling- 
bath  without  regard  to  consequences.  That  such  work 


A    MANUAL   FOR   STEEL-USERS.  97 

does  not  always  result  in  disastrous  fractures  shows  that 
steel  does  possess  marvellous  strength  to  resist  even  the 
worst  disregard  of  rules  and  facts. 

On  the  other  hand,  the  beautiful  work  upon  the  most 
delicate  and  difficult  shapes  that  is  done  by  one  skilled  in 
the  art  cannot  but  excite  the  surprise  and  admiration  of 
the  onlooker  who  is  familiar  with  the  physics  of  steel,  and 
who  can  appreciate  the  delicacy  of  handling  required  in  the 
operation. 

There  are  a  few  simple  laws  to  observe  and  rules  to  fol- 
low which  will  lead  to  success ;  they  will  be  stated  in  this 
chapter  as  cbarly  as  may  be,  in  the  hope  of  giving  the 
reader  a  good  starting-point  and  a  plain  path  to  follow; 
but  he  who  would  become  an  expert  can  do  so  only  by 
travelling  the  road  carefully  step  by  step.  The  hair-spring 
of  a  watch,  or  a  little  pinion  or  pivot,  so  small  that  it 
can  only  be  seen  through  a  magnifying-glass,  the  ex- 
quisitely engraved  die  costing  hundreds  or  thousands  of 
dollars,  and  the  huge  armor-plate  weighing  many  tons, 
must  all  be  hardened  and  tempered  under  precisely  the 
same  laws  and  in  exactly  the  same  way;  the  only  difference 
is  in  the  means  of  getting  at  it  in  each  case. 

Referring  now  to  properties  mentioned  in  the  previous 
chapters,  we  have  first  to  heat  the  piece  to  the  right  tem- 
perature and  then  to  cool  it  in  the  quickest  possible  way  in 
order  to  secure  the  greatest  hardness  and  the  best  grain. 
In  doing  this  we  subject  the  steel  to  the  greatest  shocks  or 
strains,  and  great  care  must  be  used. 

The  importance  of  uniformity  in  heating  for  forging  and 
for  annealing  has  been  stated,  and  it  has  been  shown  how 
an  error  in  this  may  be  rectified  by  another  and  a  more  care- 
ful heating;  when  it  comes  to  hardening,  this  uniformity 


98  STEEL: 

must  be  insisted  upon  and  emphasized,  for  as  a  rule  au 
error  hero  has  no  remedy. 

There  may  be  cases  of  bad  work  that  do  not  cause  actual 
fracture  that  can  be  remedied  by  re-heating  and  hardening, 
but  these  are  rare,  because  even  if  incurable  fracture  does 
not  occur  the  error  is  not  discovered  until  the  piece  has 
been  put  to  work  and  its  failure  develops  the  errors  of  the 
temperer. 

If  the  error  is  one  of  merely  too  low  heat,  not  producing 
thorough  hardening,  it  will  generally  be  discovered  by  the 
operator,  who  will  then  try  again  and  possibly  succeed;  but 
if  the  error  be  of  uneven  heat,  or  too  much  heat,  the  proba- 
bilities are  that  it  will  not  be  discovered  until  the  piece 
fails  in  work,  when  it  will  be  too  late  to  apply  any  remedy. 

Inferring  to  Table  I,  Chap.  V,  treating  of  specific  gravi- 
ties, it  is  clear  that  all  steel  possesses  different  specific 
gravities,  due  to  differences  of  temperature,  and  that  these 
differences  of  specific  gravity  increase  as  the  carbon  content 
increases;  it  follows  that  if  a  piece  of  steel  be  heated  un- 
evenly, internal  strains  must  be  set  up  in  the  mass,  and  it 
is  certain  that  if  steel  be  quenched  in  this  condition  violent 
strains  will  be  set  up,  even  to  the  causing  of  fractures. 

The  theory  of  this  action,  as  of  all  hardening,  is  involved 
in  discussion  which  will  be  considered  later;  in  this  chapter 
the  facts  will  be  dealt  with.  AVhen  a  piece  of  steel  is 
heated,  no  matter  how  unevenly  or  to  what  temperature 
below  actual  granulation,  and  is  allowed  to  cool  slowly  and 
without  disturbance,  it  will  not  break  or  crack  under  the 
operation.  If  a  piece  be  heated  as  unevenly  as,  say, 
medium  orange  in  one  part  and  medium  lemon  in  another, 
and  is  then  quenched,  it  will  be  almost  certain  to  crack  if 
it  contains  enough  carbon  to  harden  at  all  in  the  common 


A  MANUAL  FOR  STEEL-USERS.  99 

acceptance  of  the  term,  that  is  to  say,  file  hard  or  having 
carbon  40  or  higher. 

This  fact  is  too  well  known  to  be  open  to  discussion; 
therefore  the  quenching  of  hot  steel,  the  operation  of 
hardening,  does  set  up  violent  strains  in  steel,  no  matter 
what  the  true  theory  of  hardening  may  be. 

Referring  to  Chap.  V,  to  the  series  of  squares  represent- 
ing the  apparent  sizes  of  grain  due  to  different  tempera- 
tures, similar  results  follow  from  hardening,  with  the  ex- 
ceptions that  the  different  structures  are  far  more  plainly 
marked,  and  the  squares  should  be  arranged  a  little  differ- 
ently; they  are  shown  as  continuously  larger  in  Chap.  V, 
from  the  grain  of  the  cold  bar  up  to  the  highest  tempera- 
ture; this  is  true  if  a  bar  has  been  rolled  or  hammered 
properly  into  a  line  condition  of  grain.  Of  course  if  a  bar 
be  finished  at,  say,  medium  orange  it  will  have  a  grain  due 
to  that  heat  —  No.  3  in  the  series  of  squares.  Then  if  it  be 
heated  to  dark  orange  and  cooled  from  that  heat  it  will 
take  on  a  grain  corresponding  to  square  No.  2,  and  No.  1 
square  will  be  eliminated. 

The  series  of  squares  to  represent  hardened  grain  will 
be  as  follows  : 


The  heat  colors  being  the  same  as  before,  viz.: 

1.  The  natural  bar—  untreated. 

2.  Quenched  at  dark  orange  or  orange  red. 

3.  "         "medium  orange—  refined. 

4.  "         "  bright  orange. 

5.  «         "  dark  lemon. 

6.  "         "  medium  lemon. 

7.  «         "  bright  lemon. 

8.  "         "  very  bright  lemon  or  creamy. 


100 


STKKL: 


Heats  G,  7,  8  will  almost  invariably  produce  cracks 
although  the  pieces  he  evenly  heated. 

These  squares  do  not  represent  absolute  structures  with 
marked  divisions;  they  are  only  the  steps  on  an  incline, 
like  the  temper  numbers  in  the  carbon  series;  thus,  the 
carbon-line  is  continuous,,  but  the  temper  divisions  repre- 


sent steps  up  the  incline.  So  with  the  series  of  squares, 
the  changes  of  grain  or  structure  are  continuous,  as  repre- 
sented by  the  doubly  inclined  line;  the  squares  being 


only  the  steps  to  indicate  easily  observed  divisions.  The 
minuteness  of  the  changes  is  illustrated  by  the  fact  that  in 
a  piece  heated  continuously  from  creamy  to  dark  orange 
and  quenched,  differences  of  grain  have  been  observed 
unmistakably  on  opposite  sides  of  pieces  broken  off  not 
more  than  -J  inch  thick. 

In  practice  the  differences  due  to  the  colors  given  in  the 
list  above  are  as  plain  and  surely  marked  as  are  the  differ- 
ences in  the  structure  of  ingots  due  to  the  different 
temper  carbons  already  described. 

In  this  hardened  series  each  carbon  temper  gives  its  own 
peculiar  grain;  in  low  steel,  say  40  carbon  compared  to 


A    MANUAL   FOK   STEEL-USERS.  101 

1.00  carbon  or  higher,  No.  o  will  be  larger  and  No.  8  will 
be  smaller  in  the  low  temper  than  in  the  high — another 
illustration  of  the  fact  that  low  steel  is  more  inert  to  the 
action  of  heat  than  high  steel.  All  grades  and  all  tempers 
go  through  the  same  changes,  but  they  are  more  marked 
in  the  high  than  in  the  low  steel. 

The  grain  of  hardened  steel  is  affected  by  the  presence 
of  silicon,  phosphorus,  and  manganese,  and  doubtless  by 
any  other  ingredients,  these  three  being  the  most  common. 

It  is  in  the  grain  of  hardened  steel  that  the  conditions 
described  in  Chap.  V  as  "sappy/'  "  dry,"  and  "  fiery  "  are 
the  most  easily  and  frequently  observed,  although  the  same 
conditions  obtain  in  unhardened  steel  in  a  manner  that  is 
useful  to  an  observing  steel-user.  But  it  is  in  this  hard- 
ened condition  that  the  excellences  or  defects  of  steel  are 
brought  out  and  emphasized. 

When  a  piece  of  steel  is  heated  continuously  from 
"creamy,"  or  scintillating,  down  to  black,  or  unheated,  and 
is  then  quenched,  the  grain  will  be  found  to  be  coarsest, 
hardest,  and  most  brittle  at  the  hottest  end,  and  with  the 
brightest  lustre,  even  to  brilliancy,  and  to  become  finer  down 
to  a  certain  point,  noted  as  No.  3  in  the  series  of  sonares, 
or  at  a  heat  which  shows  about  a  medium  orange  color; 
here  the  grain  becomes  exceedingly  fine,  and  here  the  steel 
is  found  to  be  the  strongest  and  to  be  without  lustre. 
Below  this  heat  the  grain  appears  coarser  and  the  steel  is 
less  hard,  until  the  grain  and  condition  of  the  unheated  part 
are  reached.  This  fine  condition,  known  as  the  refined  con- 
dition, is  very  remarkable.  It  is  the  condition  to  be  aimed 
at  in  all  hardening  operations,  with  one  or  two  exceptions 
which  will  be  noted,  because  in  this  state  steel  is  at  its  best; 
it  is  strongest  then,  and  it  would  seem  to  be  clear  without 


102  STEEL: 

argument  that  the  finest  grain  and  the  strongest  will  hold 
the  best  at  a  fine  cutting-edge,  and  will  do  the  most  work 
with  the  least  wear,  although  a  coarser  grain  may  be  a 
little  harder,  the  coarser  and  more  brittle  condition  of  the 
latter  more  than  counterbalancing  its  superior  hardness. 

The  advantages  of  this  refined  condition  are  so  great 
that  it  is  found  to  be  well  to  harden  and  refine  mild-steel 
dies,  and  battering-  and  cutting-tools  that  are  to  be  used 
for  hot  work,  although  the  heat  will  draw  out  all  of  the 
temper  in  the  first  few  minutes,  because  the  superior 
strength  of  the  fine  grain  will  enable  the  tool  to  do  twice 
to  twenty  times  more  work  than  an  nnhardened  tool. 

The  refining-heat,  like  most  other  properties,  varies  with 
the  carbon;  the  medium  orange  given  is  the  proper  heat 
for  normal  tool-steel  of  from  about  90  to  110  carbon. 
Steel  of  150  carbon  will  refine  at  about  a  dark  orange,  and 
steel  of  50  to  60  carbon  will  require  about  a  bright  orange 
to  refine  it. 

This  range  is  small,  but  it  must  be  observed  and  worked 
to  if  the  best  results  are  desired. 

A  color-blind  person  can  never  learn  to  harden  steel 
properly. 

In  studying  this  phenomenon  of  refining,  the  conclusion 
was  reached  that  it  occurred  at  or  immediately  above  the 
temperature  that  broke  up  the  crystalline  condition  of  cold 
steel  and  brought  it  fairly  into  the  second,  the  plastic  con- 
dition. Farther  observation  led  to  the  conclusion  that  the 
coarser  grain  and  greater  hardness  caused  by  higher  heats 
were  due  to  the  gradual  change  from  plastic  toward  granu- 
lar condition  that  takes  place  as  the  heat  increases.  Later 
investigations  have  given  no  reason  for  changing  these  con- 
clusions. 


A   MANUAL   FOR  STEEL-USERS.  103 

When  the  phenomenon  of  recalescence  was  observed  and 
investigated  by  Osmond  and  others,  different  theories  were 
advanced  in  explanation. 

Langley  concluded  that  if  recalescence  occurred  ut  the 
change  from  a  plastic  to  a  crystalline  condition,  then  the 
heat  absorbed  and  again  set  free  during  such  changes 
would  account  for  the  visible  phenomenon  of  recalescenw. 

Again,  if  it  should  prove  that  recalescence  occurred  at 
the  refining  point,  the  conjunction  of  these  phenomena 
would  indicate  strongly,  first,  that  refining  does  occur  at 
the  point  where  this  change  of  structure  is  complete  in  the 
reverse  order,  from  crystalline  to  plastic;  and  second,  the 
first  being  true,  recalescence  would  be  explained  as  stated, 
as  indicating  the  inevitable  absorption  and  emission  of  heat 
due  to  such  a  change. 

Langley  fitted  up  an  electric  apparatus  for  heating  steel, 
in  a  box  so  placed  that  the  light  was  practically  uniform, 
that  is,  so  that  bright  sunlight,  or  a  cloudy  sky,  or  passing 
clouds  would  not  affect  seriously  the  observation  of  heat- 
colors. 

Pieces  of  steel  were  heated  far  above  recalescence,  up  to 
bright  lemon,  and  then  allowed  to  cool  slowly;  in  this  way 
recalescence  was  shown  clearly. 

It  was  found  to  occur  at  the  refining  heat  in  every  case, 
shifting  for  different  carbons  just  as  the  refining  heat 
shifts. 

Immediately  under  the  pieces  being  observed  was  a 
vessel  of  water  into  which  the  pieces  could  be  dropped  and 
quenched.  After  observing  the  heating  and  cooling  until 
the  eye  was  well  trained,  pieces  were  quenched  at  different 
heats  and  the  results  were  noted.  It  was  found  that  in  the 
ascending  heats  no  great  hardness  was  produced  until  the 


104  STEEL: 

recalescence  heat  was  reached  or  passed  slightly;  and  in 
the  descending  heat  excessive  hardening  occurred  at  a  little 
below  the  recalescent  heat,  although  no  such  hardening 
occurred  at  that  color  during  ascending  heats.  This  ap- 
parent anomaly  is  due  simply  to  lag.  If,  in  ascending,  the 
piece  be  held  for  a  few  moments  at  the  recalescent  point, 
no  increase  being  allowed,  and  then  it  be  quenched,  it  will 
harden  thoroughly  and  be  refined.  If,  in  descending,  the 
cooling  be  arrested  ut  a  little  below  the  recalescence  for  a 
few  moments,  neither  increase  nor  decrease  being  allowed, 
and  then  the  piece  be  quenched,  it  will  not  harden  any 
better  than  if  it  be  quenched  immediately  upon  reaching 
the  same  heat  in  ascending. 

Time  must  be  allowed  for  the  changes  to  take  place,  and 
lag  must  be  provided  for. 

These  experiments  show  that  refining  and  recalescence 
take  place  at  the  same  temperature. 

AS   TO    IIARDXESS. 

Prof.  J.  W.  Langley  showed  by  sp.  gr.  determinations 
that  steel  quenched  from  212°  F.  in  water  at  60°  F. 
showed  the  hardening  effect  of  such  quenching,  the  differ- 
ence of  temperature  being  only  152°  F. 

Prof.  S.  P.  Langley,  of  the  Smithsonian,  proved  the  same 
to  be  true  by  delicate  electrical  tests,  and  these  again  were 
confirmed  by  Prof.  J.  W.  Langley  in  the  laboratory  of  the 
Case  School  of  Sciences. 

A  piece  of  refined  steel  will  rarely  be  hard  enough  to 
scratch  glass.  A  piece  of  steel  quenched  from  creamy  heat 
will  almost  always  scratch  glass.  The  maximum  hardness 
is  produced  by  the  highest  heat,  or  when  temperature  minus 


A    MANUAL   FOR   STEEL-USERS.  105 

cold  is  a  maximum;  the  least  hardness  is  found  by  quench- 
ing at  the  lowest  heat  above  the  cooling  medium,  or  when 
temperature  minus  cold  is  a  minimum — the  time  required 
to  quench  being  a  minimum  in  both  cases. 

What  occurs  between  these  limits  ?  Is  the  curve  of  hard- 
ness a  straight  line,  or  an  irregular  line? 

Let  a  piece  of  steel  be  heated  as  uniformly  as  possible 
from  a  creamy  heat  at  one  end  to  black  at  the  other,  and 
then  be  quenched. 

Now  take  a  newly  broken  hard  file  and  draw  its  sharp 
corner  gently  and  firmly  over  the  piece,  beginning  at 
the  black-heated  end.  The  file  will  take  hold,  and  as 
it  is  drawn  along  it  will  be  felt  that  the  piece  becomes 
slightly  harder  as  the  file  advances,  until  suddenly 'it  will 
slip,  and  no  amount  of  pressure  will  make  it  take  hold 
above  that  point.  The  piece  has  become  suddenly  file 
hard. 

Next  try  the  same  thing  with  a  diamond;  the  diamond 
will  cut  easily  until  the  point  is  reached  where  the  file 
slipped,  then  there  will  be  found  a  great  increase  of  hard- 
ness. 

From  this  point  to  the  end  of  the  piece  it  is  observed 
readily  by  the  action  of  the  diamond  that  there  is  a  gradual 
increase  of  hardness  from  the  hump  to  the  end  of  the  piece 
to  the  creamy-heated  end.  Attempts  were  made  to  meas- 
ure this  curve  of  hardness  by  putting  a  load  on  the  dia- 
mond and  dragging  it  over  the  piece;  but  no  diamond  ob- 
tainable would  bear  a  load  heavy  enough  to  produce  a 
groove  that  could  be  measured  accurately  by  micrometer. 
An  examination  of  such  a  groove,  through  a  strong  magni- 
fying-glass  revealed  the  conditions  plainly  ;  the  groove  of 


106  STEEL: 

hardness  may  be  illustrated  on  au  exaggerated  scale  ;  thus; 


The  next  question  was,  Where  does  this  hump  occur,  and 
what  is  the  cause  of  it? 

Careful  observation  showed  that  it  occurred  at  the  point 
of  recalescence,  at  the  refining-point.  This  word  point 
must  not  be  taken  as  space  without  dimension  in  this  con- 
nection; it  is  used  in  the  common  sense  of  at  or  adjacent 
to  a  given  place.  There  is  of  course  a  small  allowable 
range  of  temperature  above  any  given  exact  point  of  recal- 
escence, such  as  655°  C.  or  12 11°  F. 

By  superimposing  Langley's  curves  of  cooling  and  of 
hardening  (see  Trans.  Am.  Soc.  Civ.  Eng.,  Vol.  XXVII,  p, 
403),  the  relation  between  recalescence  and  the  hardening- 
hump  is  obvious. 

TIME  IN  COOLINQ 


1170° 

f 


'CURVE  OF 
HARDENING 


INCREASE  IN  HARQNESS- 


A  MANUAL   FOR  STEEL-USERS.  107 

It  is  safe  to  say  that  experience  proves  that  the  refined 
condition  is  the  best  for  all  cutting-tools  of  every  shape 
and  form. 

It  seems  to  be  obvious;  the  steel  is  then  in  its  strongest 
condition,  and  when  the  grain  is  finest,  the  crystals  the 
smallest,  a  fine  edge  should  be  the  most  enduring,  because 
there  is  a  more  intimate  contact  between  the  particles. 
That  a  steel  will  refine  well,  and  be  strong  in  that  con- 
dition is  the  steel-maker's  final  test  of  quality. 

No  steel-maker  who  has  a  proper  regard  for  the  charac- 
ter of  his  product  will  accept  raw  material  upon  mere  anal- 
ysis; analysis  is  of  the  utmost  importance,  for  material 
for  steel-making  must  be  of  a  quality  that  will  produce  a 
certain  quality  of  steel,  or  the  result  will  be  an  inferior 
product.  This  applies  to  acid  bessemer  and  open-hearth, 
and  to  crucible-steel  especially;  the  basic  processes  admit 
of  a  reduction  of  phosphorus  not  obtainable  in  the  others. 

In  making  fine-tool  steel  a  bad  charge  in  the  pot  inevi- 
tably means  a  bad  piece  of  steel.  It  may  happen  also  that 
an  iron  of  apparently  good  analysis  will  not  produce  a 
really  fine  steel;  then  there  must  be  a  search  for  unusual 
elements,  such  as  copper,  arsenic,  antimony,  etc.,  or  for 
dirt,  left  in  the  iron  by  careless  working.  The  refming- 
test  then  is  as  necessary  as  analysis,  for  if  steel  will  not 
refine  thoroughly  it  will  not  make  good  tools.  Battering- 
tools,  such  as  sledges,  hammers,  flatters,  etc.,  should  be 
refined  carefully,  for  although  their  work  is  mainly  com- 
pressive  they  are  liable  to  receive,  and  do  get,  blows  on 
the  corners  and  edges  that  would  ruin  them  if  they  were 
not  in  the  strongest  condition  possible. 

The  reasons  for  refining  hot-working  tools  have  been 
stated  already.  Engraved  dies  for  use  in  drop-presses 


108 


STEEL: 


where  they  are  subjected  to  heavy  blows  are  undoubtedly 
in  the  most  durable  condition  when  they  are  refined,  but 
they  are  subjected  not  only  to  impact,  but  to  enormous 
compression,  and  therefore  they  must  be  hardened  deeply. 
When  a  die-block  is  heated  so  as  to  refine,  and  then  is 
quenched,  it  hardens  perfectly  on  the  surface  and  not  very 
deeply,  and  it  is  quite  common  in  such  a  case  to  see  a  die 
crushed  by  a  few  blows:  the  hardened  part  is  driven  bodily 
into  the  soft  steel  below  it,  and  the  die  is  ruined;  thus: 


CRACK_ 


To  avoid  this,  such  a  die  should  be  heated  to  No.  5,  or  a 
dark  lemon,  and  quenched  suddenly  in  a  large  volume  of 
rushing  water. 

Tt  will  then  have  the  enormous  resistance  to  compres- 
sion that  is  so  well  known  in  very  hard  steel,  and  it  will 
be  hardened  so  deeply  that  the  blow  of  the  hammer  will 
not  crush  through  the  hard  part.  This  is  the  best  con- 
dition, too,  of  an  armor-plate  that  is  to  resist  the  impact  of 
a  projectile. 

It  will  be  brittle,  a  light  blow  of  a  hammer  will  snip  the 
corners,  but  it  cannot  be  crushed  by  ordinary  work.  Dies 
made  in  this  way  have  turned  out  thousands  of  gross  of 
stamped  pieces,  showing  no  appreciable  wear. 

To  harden  a  die  in  this  way  is  a  critical  operation,  be- 
cause ihe  strains  are  so  enormous  that  a  very  trifling  un- 
evenness  in  the  heat  will  break  the  piece,  but  the  skill  of 
expert  temperers  is  so  great  that  they  will  harden  hun- 


A   MANUAL   FOR  STEEL-USERS.  109 

dreds  of  dies  in  this  way  and  not  lose  one  if  the  steel  be 
sound. 

HEATING   FOR   HARDENING. 

A  smith  can  heat  an  occasional  piece  for  hardening,  in 
his  ordinary  fire  by  using  care  and  taking  a  little  time. 
Where  there  are  many  pieces  to  be  hardened,  special  fur- 
naces should  be  used. 

For  thousands  of  little  pieces,  such  as  saw-teeth  or  little 
springs,  a  large  furnace  with  a  brick  floor,  and  so  arranged 
that  the  flame  will  not  impinge  on  the  pieces,  is  good. 

The  operator  can  watch  the  pieces,  and  as  soon  as  any 
come  to  the  right  color  he  can  draw  them  out,  letting 
them  drop  into  the  quenching- tank,  which  should  be  right 
under  the  door  or  close  at  hand. 

For  twist  drills,  reamers,  etc.,  a  lead  bath,  or  a  bath  of 
melted  salt  and  soda,  is  used.  The  lead  bath  is  the  best 
if  care  be  taken  to  draw  off  the  fumes  so  as  not  to  poison 
the  heaters.  Because  a  bath  of  this  kind  is  of  exactly  the 
right  color  at  the  top  it  is  not  to  be  assumed  that  pieces 
can  be  heated  in  it  and  hardened  without  further  atten- 
tion. 

Thousands  of  tools  are  ruined,  and  thousands  of  dollars 
are  thrown  away  annually,  by  unobserving  men  who  as- 
sume that  because  a  lead  bath  appears  to  be  exactly  the 
right  color  at  the  surface  it  is  therefore  just  right. 

A  dark  orange  color  surface  may-have  underneath  it  an 
increasingly  higher  temperature,  up  to  a  bright  lemon  at 
the  bottom,  and  tools  heated  in  such  a  bath  will  have  all 
of  the  varying  temperatures  of  the  bath;  then  cracked 
tools,  twisted  tools,  brittle  tools,  tools  too  hard  at  one  end 
and  not  hard  enough  at  the  other,  will  come  out  with  ex- 
asperating regularity. 


110  STEEL: 

All  of  this  can  be  avoided  by  a  simple  thorough  stirring 
of  the  bath,  to  be  done  as  often  as  may  be  necessary  to 
keep  it  uniform. 

In  heating  toothed  tools,  taps,  reamers,  milling-cutters, 
and  the  like,  care  should  be  taken  that  the  points  of  the  teeth 
never  get  above  the  refining-heat,  the  dark  or  medium 
orange  required.  It  is  no  easy  matter  to  do  this  except  in 
a  uniform  bath,  but  it  must  be  done.  If  the  teeth  are 
bright  lemon,  or  even  bright  orange,  when  the  body  of  the 
tool  is  at  medium  orange  refining-heat,  the  probabilities  are 
that  they  will  shell  off  from  the  hardened  tool  as  easily  as 
the  grains  from  a  cob  of  corn. 

Even  if  they  are  not  so  bad,  if  they  do  not  crack  off,  they 
will  be  coarse-grained  and  brittle;  they  will  not  hold  a 
good  edge,  and  they  will  not  do  good  work.  If  a  long  tool, 
such  as  a  drill,  etc.,  be  heated  medium  orange  on  one  side 
and  bright  orange  on  the  other, — a  difference  of  100°  to 
200°  F., — and  be  quenched,  it  will  come  out  of  the  bath 
curved  ;  it  must  be  curved.  In  quenching  a  long  tod 
which  it  is  desired  to  have  straight  it  should  be  dipped 
vertically,  so  as  to  cool  all  around  the  axis  simultaneously. 
If  such  a  tool  be  dipped  sideways,  it  will  come  out  bent. 
In  heating  edge-tools  of  all  kinds  it  is  best  to  heat  first  the 
thicker  part,  away  from  the  edge,  and  then  when  the 
body  has  come  up  to  the  refining-heat  to  draw  the  edge 
into  the  fire  and  let  it'corne  up  last ;  as  soon  as  a  uniform 
color  is  reached  quench  promptly.  If  the  edge  be  exposed 
to  the  fire  in  the  beginning  of  the  operation,  it  will  almost 
certainly  become  too  hot  before  the  thicker  parts  are  hot 
enough. 

When  a  smooth,  cylindrical  piece  is  to  be  hardened,  it 
should  be  rolled  around  from  time  to  time  while  heating, 


A  MANUAL   FOR  STEEL-USERS.  Ill 

unless  it  is  in  a  lead  bath;  if  it  be  left  to  lie  quietly  in  a 
furnace  until  it  is  hot,  it  will  have  a  soft  streak  along  the 
part  that  was  uppermost. 

The  cause  of  this  is  not  clear ;  the  fact  is  as  certain 
as  hundreds  of  tests  can  make  any  fact.  The  experiment 
can  be  made  by  re-heating  the  piece  with  the  soft  streak 
down  ;  then  the  original  soft  streak  will  come  out  hard,  and 
another  soft  streak  will  be  found  on  top.  The  changes  can 
be  rung  upon  this  indefinitely. 

A  maker  of  roller-tube  expanders  had  great  trouble  with 
his  expander-pins;  they  cut,  and  wore  out  on  one  side.  He 
tried  many  makes  and  many  tempers  of  steel  with  the  same 
result.  He  was  told  to  turn  his  pins  over  and  over  as  he 
heated  them  and  his  troubles  would  end.  He  replied: 
"Why,  of  course;  I  can  see  the  reason  and  sense  in  that." 
If  he  did  see  the  reason,  he  is  the  only  person  known,  so 
far,  who  has  done  so.  His  pins  worked  all  right  from  that 
time. 

/;*  hardening  ROUND  SECTIONS  it  is  necessary  to  use 
great  care  to  have  the  heat  perfectly  uniform  and  not  too 
high,  because  the  circular  form  is  the  most  rigid,  offering 
the  greatest  resistance  to  change.  For  this  reason  a  round 
piece  will  be  almost  certain  to  split  if  it  be  heated  above  a 
medium  orange,  or  if  it  be  heated  unevenly.  Many  a 
round  piece  is  cracked  by  a  heat,  or  by  a  little  unevenness 
of  heat,  that  another  section  would  endure  safely.  A  roll 
with  journals  is  perhaps  the  most  difficult  of  all  tools  to 
harden  successfully ;  the  most  expert  temperers  will  not 
be  surprised  at  losing  as  many  as  one  roll  in  five. 

Engraved  dies  require  to  be  hardened  without  oxidizing 
the  engraved  face,  so  that  the  finest  lines  will  be  preserved 
clear  and  clean. 


112 


STEEL: 


This  is  done  by  burying  the  engraved  face  in  carbonaceous 
material  in  such  a  way  as  to  prevent  the  flame  or  any  hot 
air  from  coming  in  contact  with  it. 

There  are  many  ways  of  doing  this,  and  many  different 
carbonaceous  mixtures  are  used  ;  one  simple,  and  known  to 
be  satisfactory,  plan  will  be  explained  as  sufficient  to  give 
any  intending  operator  a  good  starting-point. 

The  carbonaceous  material  preferred  is  burnt  leather 
powdered — and  the  older  it  is  the  better — until  it  is  reduced 
to  ash,  so  that  the  material  should  be  saved  after  each 
operation  to  be  used  again  mixed  with  enough  new  material 
to  make  up  the  necessary  quantity. 


D  is  the  die  to  be  heated  ;  B  is  an  open  box  about  two 
inches  deep  and  one  inch  larger  each  way  than  the  die; 
L  is  the  burnt  leather  packed  in  thoroughly,  and  as  full  as 
the  box  will  hold.  The  engraved  face  is  down,  embedded 
in  the  burnt  leather,  and  secure  from  contact  with  flame 
or  air. 

Sometimes  powdered  charcoal  is  used,  with  or  without  a 
mixture  of  tar,  according  to  the  fancy  of  the  operator. 

Some  operators  prefer  to  have  the  box  so  high  as  to 


A   MANUAL   FOR   STEEL-l'SERS.  113 

leave  only  the  top  surface  of  the  embedded  die  exposed, 
but  the  most  successful  workers  prefer  the  plan  sketched, 
because  they  can  see  more  of  the  die,  and  so  regulate 
better  the  even  heating. 

The  die  and  box  are  put  in  the  furnace,  and  the  heating 
is  watched,  the  die  being  turned  and  movpd  about  in  the 
furnace  so  as  to  obtain  a  perfectly  even  heat. 

When  the  right  temperature  is  reached,  the  whole  is 
withdrawn  from  the  furnace;  the  die  is  lifted  out  of  the 
box  and  plunged  into  the  water  immediately.  There 
must  be  no  delay  at  this  point  whatever;  a  few  moments' 
exposure  of  the  hot  die  to  the  air  will  result  in  oxidation 
and  scaling  of  the  engraving. 

In  heating  such  a  die  a  furnace  should  be  used.  It  can 
be  done  in  a  smith's  fire,  but  it  is  a  hazardous  plan,  and 
gives  many  chances  for  a  failure. 

A  furnace  with  an  even  bed  of  incandescent  coke  is 
good,  and  such  a  furnace  is  very  useful  for  many  other 
purposes. 

Where  many  dies  are  to  be  hardened,  the  handiest  appli- 
ance is  a  little  furnace  with  brick  floor  and  lining,  and 
heated  by  petroleum  or  gas,  so  arranged  that  the  flames 
will  not  impinge  upon  the  piece  to  be  heated. 

Such  furnaces  are  now  made  to  work  so  perfectly  that 
illuminating-gas  is  found  to  be  an  economical  fuel. 

For  quenching  there  should  be  plenty  of  water.  For 
small  dies  that  can  be  handled  easily  by  one  man  a  large 
tub  or  tank  of  water  will  answer  if  the  operator  will  keep 
the  die  in  rapid  motion  in  the  water. 

Running  water  is  the  best.  A  handy  plan  is  to  have  the 
inlet-pipe  project  vertically  a  short  distance  through  the 
bottom  of  the  tank,  producing  a  strong  upward  current 


114  STEEL: 

which  will  strike  directly  against  the  face  of  the  sub- 
merged die. 

Some  prefer  a  downward  stream;  others  a  side  stream; 
others.,  again,  prefer  a  shower-bath;  and,  again,  some  use 
side  jets. 

A  very  efficient  tank  has  a  partition  running  from  a  few 
indies  from  the  bottom  to  within  a  few  inches  of  the  sur- 
face of  the  water,  and  so  placed  as  to  separate,  say,  nine 
tenths  of  the  tank  from  one  tenth.  In  the  smaller  com- 
partment there  is  an  Archimedean  screw  driven  at  a  speed 
of  200  to  300  revolutions;  this  drives  the  Avater  under  the 
partition  and  out  over  the  top  in  a  violent  current.  The 
steel  is  quenched  in  the  larger  space.  Where  water  is  an 
item  of  expense,  this  plan  is  economical,  and  it  is  certainly 
efficient. 

An  excellent  Avay  of  quenching  large  faces,  such  as 
anvils,  is  to  have  a  tank  raised  twelve  to  fifteen  feet  from 
the  floor.  In  the  bottom  of  the  tank  is  a  pipe  with  a 
valve,  to  be  operated  by  a  lever.  The  whole  is  enclosed  in 
a  sort  of  closet  with  a  door  in  one  side.  When  the  piece  is 
hot,  it  is  placed  immediately  under  the  pipe,  the  door  is 
closed,  the  valve  is  opened,  and  a  great  body  of  water  is 
dashed  down  upon  the  face  that  is  to  be  hardened. 

A  slight  modification  of  this  plan  is  used  in  hardening 
armor-plates,  where  many  jets  are  used  to  insure  even 
quenching  of  the  large  surface.  This  plan  is  supposed  to 
be  patented,  or,  more  properly,  it  is  patented;  but  as  it  is 
very  old  and  well  known  the  patent  should  not  be  allowed 
to  disturb  anybody. 

AVater  only  has  been  mentioned  so  far  as  a  quenching 
medium,  because  it  is  the  simplest  and  the  cheapest  gen- 
erally. Oil  is  used  frequently  where  extreme  hardness  is 


A   MANUAL  FOR   STEEL-USERS.  115 

not  necessary  and  toughness  is  desirable.  Oil  gives  a  good 
hardness  with  toughness,  aud  it  is  used  almost  universally 
for  springs,  and  it  is  sometimes  used  to  toughen  railroad 
axles  and  similar  work.  The  oil  acts  more  slowly  than 
water  and  leaves  the  piece  in  more  nearly  a  tempered  con- 
dition; it  is  neither  so  hard  nor  so  brittle  as  it  would  be  if 
quenched  in  water.  Straits  fish-oil  is  good  and  cheap; 
lard-oil  gives  greater  hardness  than  fish-oil;  mineral  oil  is 
too  fiery  to  use  safely;  but  there  are  mixed  oils  in  the  mar- 
ket made  expressly  for  hardening  which  are  cheap  and 
efficient. 

If  it  is  desired  to  get  the  greatest  hardness,  brine  will 
harden  harder  than  fresh  water;  and  mercury  will  give 
the  greatest  hardness  of  all.  It  is  a  rather  expensive  cool- 
ing medium. 

Acid  added  to  water  increases  its  hardening  power;  but 
those  who  know  the  effects  of  acids  will  be  very  chary  of 
using  them. 

As  to  heating,  too  much  emphasis  cannot  be  given  to  the 
importance  of  even  temperature  throughout  the  mass. 
The  illustration  of  the  painted  piece  mentioned  in  connec- 
tion with  heating  for  forging  applies  more  forcibly  here. 
Every  piece  that  is  to  be  quenched  should  look  as  if  it 
were  covered  with  a  perfectly  even  coat  of  paint  of  the 
exact  tint  necessary  to  give  the  best  result. 

All  hardening  should  be  done  on  a  rising  temperature, 
because  then  the  grain  and  strains  cannot  be  greater  than 
those  due  to  the  highest  heat,  and  this  maximum  heat  can 
be  watched  and  kept  within  limits.  If  a  piece  be  quenched 
from  a  falling  temperature,  the  grain  and  strains  will  be 
those  due  to  the  highest  temperature,  modified  slightly  by 
the  distance  through  which  it  has  cooled,  and  always  coarser 


116  STEEL: 

and  more  brittle  than  if  quenched  at  the  same  heat  pro- 
duced by  rising  temperature.  If  by  accident  a  piece  gets 
too  hot  to  be  quenched,  it  should  be  allowed  to  go  entirely 
cold,  and  then  be  heated  again  to  the  rigbt  color. 

After  a  piece  of  steel  is  hardened  it  is  usually  tempered 
to  relieve  some  of  the  strain,  reduce  brittleness,  and  in- 
crease the  toughness. 

This  is  done  by  heating;  usually  the  piece  is  held  over 
the  fire,  or  in  contact  with  a  large  piece  of  steel  or  iron 
heated  for  the  purpose,  until  it  takes  on  a  certain  color 
which  indicates  the  degree  of  tempering  that  is  wanted. 

Where  great  numbers  of  pieces  are  to  be  tempered,  a 
bath  is  very  convenient.  Boiling  in  water  produces  only 
a  slight  tempering  sufficient  for  some  purposes.  Steaming 
under  given  pressure  will  produce  even  heating  and  uni- 
form tempering. 

When  pieces  are  quenched  in  oil,  they  can  be  tempered 
easily  and  nicely  by  watching  the  oil  that  adheres  to  them. 
When  the  oil  is  dried  off  and  begins  to  char,  the  tempering 
is  good,  about  right  for  saw-teeth.  If  the  heat  is  run  up 
until  the  oil  flashes,  the  tempering  is  pretty  thorough  and 
is  about  right  for  good  springs.  If  the  oil  be  all  burned 
off,  there  will  be  little  temper  left  except  in  very  high 
steel.  High  steel  becomes  much  harder  when  quenched 
than  low  steel;  consequently  very  high  hardened  steel  may 
be  heated  until  it  begins  to  show  color  and  still  retain  con- 
siderable hardness  or  temper,  whereas  a  milder  steel, 
under  90  or  100  carbon,  when  heated  to  such  a  degree  will 
retain  no  temper,  it  will  be  soft. 

Saw-teeth,  tap,  reamer,  and  milling-cutter  teeth,  may  be 
drawn,  and  usually  should  be  drawn,  down  until  a  file  will 
barely  catch  them;  then  they  will  do  excellent  work.  Many 


A   MANUAL   FOR  STEEL-USERS.  117 

inexperienced  temperers  are  apt  to  complain  if  such  tools 
can  be  filed  tit  all  when  drawn  to  the  proper  color,  forget- 
ful or  ignorant  of  the  fact  that  a  file  should  always  contain 
about  twice  as  much  carbon  as  a  tap  or  reamer,  and  that 
if  both  are  drawn  to  the  same  color  the  file  must  necessarily 
be  the  harder.  Such  men  often  destroy  much  good  work 
by  trying  to  get  the  tools  too  hard.  If  a  tap-tooth  be  left 
file  hard,  it  will  be  pretty  certain  to  snip  off  when  put  to 
work. 

TEMPER  COLORS. 

When  a  clean  piece  of  iron  or  steel,  hardened  or  un- 
hardened,  is  exposed  to  heat  in  the  air,  it  will  assume  differ- 
ent colors  as  the  heat  increases.  First  will  be  noticed  a 
light,  delicate  straw  color;  then  in  order  a  deep  straw, 
light  brown;  darker  brown;  brown  shaded  with  purple, 
known  as  pigeon-wing;  as  the  brown  dies  out  a  light 
bluish  cast;  light  brilliant  blue;  dark  blue;  black. 

When  black,  the  temper  is  gone.  It  is  well  established 
that  these  colors  are  due  to  thin  films  of  oxide  that  are 
formed  as  the  heat  progresses. 

These  colors  are  very  beautiful,  and  as  useful  as  they  are 
beautiful,  furnishing  an  unvarying  guide  to  the  condition 
of  hardened  steel. 

The  drawing  of  hardened  steel  to  any  of  these  colors  is 
tempering. 

So  we  have  the  different  tempers: 

Light  straw For  lathe-tools,  files,  etc. 

Straw "      "        "        "      " 

Light  brown "    taps,  reamers,  drills,  etc. 

Darker  brown "      "  "  "       " 

Pigeon-wing "    axes,  hatchets,  and  some  drills 

Light  blue "    springs 

Dark  blue "    some  springs;  but  seldom  used 


118 


STEEL: 


This  is  the  unfortunate  second  use  of  the  word  temper, 
which  must  be  borne  in  mind  if  confusion  is  to  be  avoided 
in  consulting  with  steel-makers  and  steel-workers.  The 
meanings  may  be  tabulated  thus  : 


Temper. 

Steel-maker's  Meaning. 

Steel-worker's  Meaning. 

Very  high   

150  carbon  -)- 

light  straw 

Hicrh  

100  to  120  C 

straw 

Medium 

70  to  80  C 

Mild 

40  to  60  C 

licrht  blue 

Lou- 

20  to  30  C 

Soft  or  dead  soft  

under  20  C 

black 

The  uses  given  for  temper  colors  are  not  meant  to  be  ab- 
solute; they  merely  give  a  good  general  idea;  experienced 
men  are  guided  by  results,  and  temper  in  every  case  in  the 
way  that  proves  to  be  most  satisfactory. 

DIFFERENCE    BETWEEN    CRACKS   AND    SEAMS. 

When  temperers  find  that  their  tools  are  cracking  under 
their  treatment,  they  are  apt  to  assume  that,  as  they  are 
working  in  their  ordinary  way,  there  must  be  something 
wrong  with  the  steel.  It  is  either  seamy,  or  harder  than 
usual,  or  not  uniform  in  temper,  or  it  is  of  inferior  quality. 

All  or  any  of  these  conditions  may  exist  and  be  thw 
cause  of  the  trouble;  but  every  man  should  bear  in  mind 
that  he  is  also  a  variable  quantity;  he  may  be  unwell  and 
not  see  and  observe  as  closely  as  usual;  theie  maybe  a  long 
spell  of  unusual  weather  giving  him  a  light  differing  from 
that  to  which  he  is  accustomed;  or,  as  is  often  the  case,  he 
may  simply  have  unconsciously  departed  from  the  even 
track  by  not  having  his  mind  carefully  intent  upon  the 
routine  which  has  become  a  sort  of  second  nature  to  him, 
so  that  for  a  time  he  ceases  to  think,  makes  of  himself  an 


A   MANUAL   FOR   STEEL-USERS.  119 

animated  machine,  and  the  machine  left  to  itself  does  not 
run  with  perfect  regularity. 

If  personal  pride,  egotism,  or  ill  temper  be  set  aside,  it  is 
always  easy  to  find  out  whether  the  fault  is  in  the  steel  or 
in  the  man  ;  that  once  determined  the  remedy  is  easily 
applied,  and  the  sooner  the  better  for  all  parties. 

How  to  Break  a  Tool.  Let  an  ordinary  axe  be  con- 
sidered. 


If  the  axe  be  cracked  as  shown  in  Fig.  1,  the  corners 
have  been  hotter  than  the  middle  of  the  blade;  probably 
by  snipping  the  corners  and  the  middle  and  comparing 
the  fractures  the  coarser  grain  at  the  corners  will  tell  the 
tale. 

If  the  crack  be  as  shown  in  No.  2,  the  middle  of  the 
blade  has  been  hotter  than  the  corners  :  snipping  and  com- 
paring the  grains  will  tell  the  story. 


If  the  crack  be  more  nearly  a  straight  line,  as  shown  in 
number  '3,  the  chances  are  that  there  is  a  seam  there  and 
the  steel  is -at  fault. 

How  to  Tell  a  Seam  from  a  Water-crack. — A  seam  is 
caused  by  a  gas-bubble  in  the  ingot  which  has  not  been 
closed  up  by  hammering  or  rolling;  it  always  runs  in  the 
direction  of  the  work;  in  bars  it  is  parallel  to  the  axis. 

The  walls  of  a  seam  are  always  more  or  less  smooth,  the 
surfaces  having  been  rubbed  together  under  heavy  pressure 
during  hammering  or  rolling,  and  they  are  black  usually, 
being  coated  with  oxide. 

The  walls  of  a  water-crack  are  never  smooth,  they  are 
rough  and  gritty,  and  they  may  have  any  of  the  temper 
colors  caused  by  the  action  of  water  and  heat. 

There  need  never  be  any  question  as  to  which  is  Avhich. 

If  a  long  tool  cracks  down  the  middle,  it  may  be  from 
too  much  heat,  from  seams,  or  from  a  lap. 

A  lap  is  caused  by  careless  working  under  a  hammer,  or 
by  bad  draughts  in  the  rolls,  folding  part  of  the  steel  over 
on  itself.  Laps,  like  seams,  run  parallel  to  the  axis  of  a 
bar,  and  usually  in  very  straight  lines. 

Any  long  piece  of  steel  may  be  split  in  hardening  by  too 
much  heat.  In  making  the  experiment  of  heating  a  piece 
continuously  from  scintillating,  or  creamy  color,  down  to 
black,  to  show  the  differences  of  grain  due  to  the  different 
heats,  the  sample  almost  invariably  splits  down  the  middle 
as  far  as  the  strong,  refined  grain,  or  nearly  that  far. 

As  stated  before,  a  round  bar  will  be  almost  certain  to 
split  if  it  be  heated  up  to  medium  lemon,  although  a 
square  bar  may  endure  the  same  heat  without  cracking. 

An  examination  of  the  walls  of  a  split  will  settle  at  once 
whether  it  is  a  seam,  a  lap,  or  a  water-crack, 


A    MANUAL    FOtt   STEEL-USERS.  121 

A  scam  will  not  necessarily  be  long;  its  walls  will  be 
smooth. 

A  hip  usually  runs  the  who'e  length  of  the  bar,  and  the 
walls  are  smooth. 

By  smooth  walls  of  seams  and  laps  comparative  smooth- 
ness is  meant;  they  are  sometimes  polished,  but  not  always, 
and  they  are  never  granular  like  the  walls  of  water-cracks. 

If  the  split  be  a  water-crack,  the  walls  will  be  rough  and 
granular. 

After  a  temperer  has  straightened  himself  out,  and 
brought  his  work  to  usual  accuracy  and  uniformity,  if  his 
tools  continue  to  crack  and  indicate  weakness  in  the  steel, 
it  is  time  for  him  to  suspect  the  character  of  his  material 
and  to  require  the  steel-muker  to  either  show  up  the  faults 
in  tempering,  or  improve  the  quality  of  his  product. 

A   WORD   FOR  THE   WORKMAN. 

Give  him  a  chance.  A  steel-worker  to  be  expert  must 
have  a  well-trained  eye  and  know  how  to  use  it.  He  must 
work  with  delicate  tints,  ranging  in  the  yellows  from 
creamy  yellow  to  dark  orange  or  orange  red  as  extremes, 
and  most  of  his  work  must  be  done  between  bright  lemon 
and  medium  orange  in  forging,  and  between  rather  dark 
to  medium  orange,  or  possibly  nearly  light  orange,  when 
hardening  and  tempering. 

Probably  in  no  other  business  is  there  such  ridiculous 
waste  as  is  often  found  in  steel-working  where  the  manu- 
facturer economizes  in  his  blacksmiths. 

A  large,  wealthy  railroad. condemns  a  brand  of  steel.  The 
steel-maker  goes  to  the  shop  and  is  informed  by  a  bright, 
intelligent  blacksmith  that  the  steel  will  not  make  a  track- 


123  STEEL: 

chisel.  It  is  a  hot  summer  day;  the  smith  is  working  over 
a  huge  fire  with  a  large  piece  of  work  in  the  middle  of  the 
fire  and  a  number  of  small  pieces  of  steel  stuck  in  the  edge 
of  the  fire. 

He  is  welding  large  iron  frog-points,  and  in  the  interval 
he  is  filling  a  hurried  order  for  four  dozen  track-chisels  for 
which  the  trackmen  are  waiting.  He  is  not  merely  forging 
the  chisels,  he  is  hardening  and  tempering  them.  The 
glare  of  the  welding-work  makes  him  color-blind,  the  hurry 
gives  him  no  time  for  manipulation,  and  the  trackmen 
have  no  chisels. 

After  a  thorough  expression  of  sympathy  for  the  smith 
the  steel-maker  turns  upon  the  foreman  and  master  me- 
chanic, and  gives  them  such  a  tongue-lashing  that  they 
turn  away  silenced  and  ashamed. 

Page  after  page  of  such  cases  could  be  written,  but  one 
should  be  enough. 

A  steel-maker  has  a  thoroughly  skilled  and  expert  steel- 
worker;  he  rushes  into  the  shop  and  says,  "  Mike,  refine 
this  right  away,  please;  I  want  to  know  what  it  is." 

Mike  replies,  "I  will  do  that  to-morrow;  I  am  welding 
to-day. " 

That  is  entirely  satisfactory;  those  men  understand  one 
another,  and  they  know  a  little  something  about  their 
business. 

A  temperer  should  do  no  other  work  when  he  is  heating 
for  hardening,  and  he  should  always  be  allowed  to  use  as 
much  time  about  it  as  he  pleases,  assuming  that  he  is  a 
decently  honest  man  who  prefers  good  work  to  bad;  and  as 
a  rule  such  honest  men  are  in  the  majority,  if  they  are 
given  a  fair  chance. 


A  MANUAL  FOR  STEEL-USERS.  123 


IX. 


ON  THE  SURFACE. 

THE  condition  of  the  surface  of  steel  lias  much  to  do 
with  its  successful  hardening  and  working. 

A  slight  film  adherent  to  the  surface  of  steel  will 
prevent  its  hardening  properly;  the  steel  may  harden 
under  such  a  film  and  not  be  hard  upon  the  immediate 
surface,  and,  as  in  almost  every  case  a  hard,  strong  surface 
is  necessary  to  good  work,  it  is  important  that  a  piece  of 
steel  to  harden  well  should  have  a  clean  surface  of  sound 
steel. 

It  has  been  stated  already  that  all  bars  and  forgings  of 
steel  have  upon  the  surface  a  coat  of  oxide  of  iron,  and  im- 
mediately beneath  this  a  thin  film  of  decarbonized  iron. 

Neither  of  these  substances  will  harden,  and  in  every 
case  where  a  hard-bearing  surface  or  a  keen-cutting  edge 
is  desired  these  coatings  must  be  removed.  Polished 
drill-wire  and  cold-rolled  spring-steel  for  watches,  clocks, 
etc.,  should  have  perfect  surfaces,  and  it  is  the  duty  of 
steel-makers  to  turn  them  out  in  that  condition.  All  black 
steel,  or  hot-finished  steel,  contains  these  coatings. 

In  the  manufacture  of  railroad,  wagon,  and  carriage 
springs  it  is  not  necessary  or  customary  to  pny  any  atten- 
tion to  these  coatings  ;  the  body  of  the  steel  hardens  well, 
giving  the  required  resilience  and  elasticity,  so  that  au  un* 


124  STEEL: 

hardened  coat  of  .01  to  .001  inch  thick  does  no  harm.  To 
all  bearing-surfaces  and  cutting-edges  such  coatings  are 
fatal. 

The  ordinary  way  of  preparing  steel  is  to  cut  the  skin 
off,  and  this  is  sufficient  if  enough  be  take  off ;  it  happens 
often  that  a  purchaser,  in  pursuit  of  economy  and  unaware 
of  the  importance  of  this  skin,  orders  his  bars  or  forgings 
so  close  -to  size  that  when,  they  are  finished  the  decarbon- 
ized skin  is  not  all  removed,  and  the  result  is  an  expensive 
tap,  reamer,  milling-cutter,  or  some  tool  of  that  sort  with 
the  points  of  the  teeth  soft  and  worthless. 

In  small  tools  -fa  inch,  in  medium-size  tools,  say  up  to 
two  or  three  inches  in  diameter,  £  inch  cut  off  should  be 
plenty  ;  in  large  tools  and  dies,  especially  in  shaped  forg- 
ings, it  would  be  wiser  to  cut  away  T\  inch. 

In  many  cases  sufficient  hardness  can  be  obtained  by 
pickling  off  the  surface-scale,  but  this  will  not  do  where 
thorough  hardening  is  required,  because  the  acid  does  not 
remove  the  thin  decarbonized  surface.  It  seems  to  be  im- 
practicable to  remove  the  decarbonized  skin  by  the  action 
of  acid,  for  if  the  steel  be  left  in  the  acid  long  enough  to 
accomplish  this  the  acid  will  penetrate  deeper,  oxidizing 
and  ruining  the  steel  as  it  advances. 

Grinding  is  frequently  resorted  to,  being  quicker  and 
cheaper  than  turning,  planing,  or  milling. 

When  grinding  is  used,  care  must  be  taken  not  to  glaze 
the  surface  of  the  steel,  or  if  it  should  be  glazed  the  glaze 
must  be  removed  by  filing  or  scraping. 

In  the  manufacture  of  files  it  is  customary  to  grind  the 
blanks  after  they  are  forged  and  before  the  teeth  are  cut. 

After  the  blanks  are  ground  they  are  held  up  to  the 
light  and  examined  carefully  for  glaze.  Every  blank  that 


A   MANUAL   FOR   STEEL-USERS.  125 

shows  by  the  flash  of  light  that  it  is  glazed  is  put  to  one 
side;  then  these  glazed  blanks  are  taken  by  other  opera- 
tives and  filed  until  all  traces  of  glazo  are  removed.  The 
file-maker  will  explain  that  if  this  be  not  done  the  files 
when  hardened  will  be  soft  at  the  tips  of  the  teeth  over 
the  whole  of  the  glazed  surface.  This  inspection  and  filing 
of  blanks  involves  considerable  expense,  and  it  is  certain 
that  such  an  expense  would  not  be  incurred  if  it  were  not 
necessary. 

This  glaze  does  not  appear  to  be  due  to  burning,  at  least 
the  stones  are  run  in  water  ;  the  blanks  are  handled  by  the 
bare  hands  of  the  grinders,  and  do  not  appear  to  be  hot. 

After  pieces  are  hardened  and  tempered  they  frequently 
require  grinding  to  bring  them  to  exact  dimensions.  This 
is  usually  done  on  emery-wheels  with  an  abundance  of 
water,  and  as  no  temper  colors  are  developed  indicating 
heat  it  is  assumed  that  no  harm  can  be  done. 

Just  here  much  valuable  work  is  destroyed.  The  tem- 
pered piece  is  put  on  the  wheel,  in  a  "  flood  of  water"  ;  the 
work  is  rushed,  and  the  piece  comes  out  literally  covered 
with  little  surface-cracks  running  in  every  direction,  per- 
fectly visible  to  the  naked  eye.  Until  the  steel-worker 
learns  better  he  blames  and  condemns  the  steel. 

This  result  is  very  common  in  the  manufacture  of  shear- 
knives,  scissors,  shear-blades,  dies,  etc. 

Sometimes  too  a  round  bearing  or  expander-pin  is  hard- 
ened ;  examined  by  means  of  a  file  it  appears  perfectly 
hard  ;  it  is  then  ground,  not  quite  heavily  enough  to  pro- 
duce surface-cracks,  but  still  heavily,  and  on  a  glazed 
wheel.  It  is  found  now  that  the  surface  is  soft;  only  a 
thousandth-of  an  inch  or  so  has  been  cut  off,  and  the  steel 
is  condemned  at  once  because  it  will  harden  only  skin  deep. 


126  STEEL: 

Let  the  file  be  drawn  heavily  over  the  surface  and  it  will 
be  found  that  the  soft  surface  is  only  about  a  thousandth 
of  an  inch  thick,  and  underneath  the  steel  is  perfectly 
hard. 

Now  grind  slightly  on  a  sharp,  clean  wheel  and  re-harden  ; 
the  surface  will  be  found  to  be  perfectly  hard.  Ground 
heavilv  again  on  the  glazed  wheel,  it  will  become  soft,  as 
before.  These  operations  can  be  repeated  with  unvarying 
results  until  the  whole  piece  is  ground  away. 

These  difficulties  occur  more  with  emery-wheels  than 
with  grindstones,  either  because  emery-wheels  glaze  more 
easily  than  grindstones,  or  because,  owing  to  their  superior 
cutting  powers  under  any  circumstances,  they  are  more 
neglected  than  grindstones. 

Experience  shows  that  these  bad  results  occur  almost  in- 
variably on  glazed  wheels.  It  is  rare  to  find  any  bad  work 
come  off  from  a  clean,  sharp  wheel,  unless  the  pressure  has 
been  so  excessive  as  to  show  that  the  operator  is  either 
foolish  or  stupid. 

The  remedy  is  simple  :  Keep  the  wheels  clean  and  sharp. 

Many  grinders  who  understand  this  matter  will  not  run 
any  wheel  more  than  one  day  without  dressing,  nor  even  a 
whole  day  if  the  work  is  continuous  and  they  have  reason 
to  apprehend  danger. 

A   FEW   WORDS   IX    EEGAHP   TO   PICKLIXG. 

Pickling  is  the  placing  of  steel  in  a  bath  of  dilute  acid 
to  remove  the  scale.  It  is  a  necessary  operation  in  wire- 
making  and  for  many  other  purposes,  and  it  may  be 
hastened  by  having  the  acid  hot. 

Sulphuric  acid  is  used  generally;  it  is  efficient  and  cheap. 
When  thin  sheets  are  to  be  pickled,  the  acid  should  not  be 


A   MANUAL    FOR  STEEL-USERS.  127 

too  hot,  or  it  will  raise  a  rash  all  over  the  sheet  in  many 
eases.  This  indicates  some  unsoundness  in  the  steel,  the 
presence  probably  of  innumerable  little  bubbles  of  oc- 
cluded gases.  This  is  possibly  true,  yet  the  same  sheets 
pickled  properly  and  brought  out  smooth  will  polish  per- 
fectly, or  if  cut  up  will  make  thousands  of  little  tools  that 
will  show  no  evidence  of  nnsoundness. 

Steel  should  never  be  left  in  the  pickling-bath  any 
longer  than  is  necessary  to  remove  the  scale;  it  seems 
unnecessary  to  warn  readers  that  the  acid  will  continue  to 
act  on  the  steel,  eat  the  steel  after  the  scale  is  removed. 
When  taken  from  the  pickle,  the  steel  should  be  washed 
in  limewater  and  plenty  of  clean  running  water;  but  this 
does  not  take  out  all  of  the  acid.  It  should  then  be  baked 
for  several  hours  at  a  heat  of  400°  to  450°  F.  to  decompose 
the  remaining  acid.  This  is  just  below  a  bluing  heat,  and 
it  does  not  discolor  or  oxidize  the  surface.  It  is  known  as 
the  sizzling-heat,  the  heat  that  the  expert  laundry- woman 
gets  on  her  flat-iron  which  she  tests  with  her  moistened 
finger. 

Acid  if  not  taken  off  completely  will  continue  to  act 
upon  and  rot  the  steel;  how  far  this  will  go  on  is  not 
known  exactly;  for  instance,  it  is  not  known  whether  if  a 
block  six  inches  cube  were  pickled  and  merely  washed,  the 
remaining  acid  would  penetrate  and  rot  the  whole  mass  or 
not.  There  must  be  some  relation  between  the  mass  of 
the  steel  and  the  power  of  a  small  amount  of  acid  to  pene- 
trate. 

The  power  of  acid  can  be  illustrated  on  the  other  ex- 
treme :  A  lot  of  watch-spring  steel  is  finished  in  long 
coils  and  .010  inch  thick ;  when  last  pickled,  the  baking 
was  neglected  ;  the  steel  is  tough,  it  hardens  well,  and 


128  STEEL: 

when  tempered  it  is  springy  and  strong;  by  all  of  the  tests 
it  is  just  right  in  every  coil.  It  is  shipped  away  and  in 
three  or  four  weeks  the  spring-maker  begins  work  on  it. 
lie  reports  at  once  that  it  is  rotten  and  worthless,  it  will 
not  make  a  spring  at  all,  and  he  is  angry.  The  steel  is 
returned  to  the  maker  and  lie  finds  the  report  true:  the 
steel  is  rotten  and  worthless.  Then  by  diligent  inquiry  be 
finds  that  the  last  baking  was  omitted,  and  he  pockets  his 
loss,  sending  an  humble  apology  to  the  irate  spring-maker. 
Whether  the  residual  acid  can  ruin  a  large  piece  of  steel 
or  not  need  not  be  considered  when  the  simple  operation 
of  baking  will  remove  the  possibility  of  harm. 


A  MANUAL  FOR  STEEL-USERS.  129 


X. 

IMPURITIES  IN  STEEL. 

ANY  elements  in  steel  which  reduce  its  strength  or 
durability  in  any  way  may  be  classed  as  impurities. 

A  theoretical  ideal  of  pure  steel  is  a  compound  of  iron 
and  carbon;  it  is  an  ideal  that  is  never  reached  in  practice, 
but  it  is  one  that  is  aimed  at  by  many  manufacturers  and 
consumers,  because  experience  shows  that,  especially  in 
high  steels,  the  more  nearly  it  is  attained  the  more  reliable 
and  safe  is  the  product. 

All  steel  contains  silicon,  phosphorus,  sulphur,  oxygen, 
hydrogen,  and  nitrogen,  none  of  which  add  any  useful 
property  to  the  material.  It  is  admitted  that,  starting 
with  very  small  quantities  of  silicon  or  phosphorus  in  mild 
steel,  small  additions  of  either  element  will  increase  the 
tensile  strength  of  the  steel  perceptibly  up  to  a  given 
amount,  and  that  then  the  addition  of  more  of  either  one 
will  cause  a  reduction  of  strength.  The  same  increase  of 
strength  can  be  obtained  by  the  addition  of  a  little  carbon, 
producing  a  much  more  reliable  material.  It  is  not  known 
that  even  such  slight  apparent  gain  in  strength  can  be 
made  by  using  oxygen,  nitrogen,  or  hydrogen. 

Manganese  is  present  in  all  steel  as  a  necessary  ingredi- 
ent, it  gives  an  increase  in  strength  in  the  same  way  as 
phosphorus,  and  when  increased  beyond  a  small  limit  it 
causes  brittleness.  Hadfield's  manganese  steel  is  a  unique 


130  STEEL: 

material,  not  to  be  considered  in  connection  with  the  ordi- 
nary steel  of  commerce. 

Webster's  experiments  are  perhaps  the  most  complete  of 
any  that  show  the  effects  of  small  increases  of  silicon, 
phosphorus,  sulphur,,  and  manganese,  but  as  these  are  not 
completed  they  are  not  quoted  here,  because  Mr.  Webster 
may  reach  additional  and  different  results  before  these 
pages  are  printed. 

The  chief  bad  qualities  of  steel  that  are  caused  by  these 
impurities  are  known  as  "red-shortness,"  "  cold-shortness/' 
and  "  hot-shortness." 

A  steel  is  called  red-short  when  it  is  brittle  and  friable 
at  what  is  known  commonly  as  a  low  red  heat — "cherry 
red,"  "  orange  red." 

Red-shortness  is  caused  chiefly  by  sulphur  or  by  oxygen; 
many  other  elements  may  produce  the  same  effects;  it 
seems  probable  that  nitrogen  may  be  one  of  these,  but  the 
real  action  of  nitrogen  is  as  yet  obscure. 

A  red-short  steel  is  difficult  to  work;  it  must  be  worked 
at  a  high  heat — from  bright  orange  up  to  near  the  heat  of 
granulation — or  it  will  crack.  When  hardened,  it  is  almost 
certain  to  crack.  When  red-short  steel  is  worked  with 
care  into  a  sound  condition,  it  may  when  cold  be  reason- 
ably strong,  but  hardly  any  engineer  of  experience  would 
be  willing  to  trust  it. 

Hot-short  steel  is  that  which  cannot  be  worked  at  a  high 
heat,  say  above  a  medium  to  light  orange,  but  which  is  gen- 
erally malleable  and  works  soundly  at  medium  orange 
down  to  dark  orange,  or  almost  black. 

This  is  a  characteristic  of  most  of  the  so-called  alloy 
steels,  or  steels  containing  considerable  quantities  of  tung- 
sten, manganese,  or  silicon.  It  is  claimed  that  chrome 


A   MANUAL   FOR   STEEL-USERS.  131 

steel  may  be  worked  at  high  heats  and  that  it  is  less  easily 
injured  in  the  fire  than  carbon  steel.  This  is  not  within 
the  author's  experience.  It  is  this  property  of  hot-short- 
ness that  makes  the  alloy  steels  so  expensive;  the  ingots 
cannot  be  heated  hot  enough  nor  worked  heavily  enough 
to  close  up  porosities,  and  therefore,  there  is  a  heavy  loss 
from  seams. 

The  range  of  heat  at  which  they  can  be  worked  is  so 
small  that  many  re-heatings  ai'e  required,  increasing  greatly 
the  cost  of  working. 

As  compared  to  good  carbon  steel  they  are  liable  to 
crack  in  hardening,  and  when  hardened  they  are  friable, 
although  they  may  be  excessively  hard. 

Cold-sJiort  steel  is  steel  which  is  weak  and  brittle  when 
cold,  either  hardened  or  nnhardened.  Of  those  which  are 
always  found  in  steel,  phosphorus  is  the  one  well-known 
element  which  produces  cold-shortness. 

It  is  clear  that  no  one  can  have  any  use  for  cold-short 
steel. 

Red-short  or  hot  short  s(eel  may  be  of  some  use  when 
worked  successfully  into  a  cold  condition,  but  cold-short 
steel  is  to  be  avoided  in  all  cases  where  the  steel  is  used 
ultimately  cold. 

If  the  theoretically  perfect  steel  is  a  compound  of  iron 
and  carbon,  it  cannot  be  obtained  in  practice,  and  the  only 
safeguard  is  to  fix  a  maximum  above  which  other  elements 
are  not  to  be  tolerated. 

In  tool-steel  of  ordinary  standard  excellence  such  maxi- 
mum should  be  .02  of  one  per  cent ;  it  may  be  worked  to 
easily  and  economically,  except  perhaps  in  silicon,  which 
element  is  generally  given  off  to  some  extent  by  the  cruci- 
ble; it  should  be  kept  as  low  as  possible,  however,  say  well 


132  STEEL: 

under  10,  one  tenth  of  one  per  cent.  Some  people  cluiin 
that  :i  little  higher  silicon  makes  steel  sounder  and  better; 
but  any  expert  temperer  will  soon  observe  the  difference 
between  steels  of  .10  and  .01  silicon.  For  the  highest  and 
best  grade  of  tool-steel  the  maximum  should  be  the  least 
attainable.  Every  one  hundredth  of  one  per  cent  of  phos- 
phorus, silicon,  or  sulphur  will  show  itself  in  fine  tool-steel 
when  it  is  hardened.  It  is  assumed,  of  course,  that  such 
impurities  as  copper,  antimony,  arsenic,  etc.,  exist  only  as 
mere  traces,  or  not  at  all. 

As  oxvgen  must  be  at  a  minimum,  no  one  has  yet  suc- 
ceeded in  making  a  really  fine  tool-steel  from  the  products 
of  the  Bessemer  or  of  the  open-hearth  process. 

The  removal  of  the  last  fractions  of  these  impurities  is 
difficult  and  expensive  ;  for  instance,  a  steel  melting  iron  of 

Silicon 03  to  .06 

Phosphorus 03  "  .02 

Sulphur 002  or  less 

may  be  bought  for  2  cents  a  pound  or  less,  whereas  an 
iron  of 

Silicon <  .02 

Phosphorus  <  .01 

Sulphur trace 

can  hardly  be  bought  for  less  than  5  cents  a  pound. 

This  difference  of  three  cents  a  pound  is  justifiable  when 
the  highest  grade  of  tool-steel  is  to  be  made;  and  it  would 
be  silly  to  require  any  such  material  in  any  spring,  ma- 
chinery,  or  structural  steel. 


A    MANUAL   FOR   STEEL-USERS.  133 

In  addition  to  these  impurities  there  are  other  difficulties 
to  be  guarded  against,  chief  among  which  is  an  uneven 
distribution  of  elements. 

In  all  steel  there  is  some  segregation;  that  is  to  say,  as 
the  liquid  metal  freezes,  the  elements  are  to  some  extent 
squeezed  out  and  collected  in  that  part  of  the  ingot  which 
congeals  last.  It  is  claimed  that  in  the  Bessemer  and 
Open-hearth  processes  any  ferro-silicon  added  to  quiet  a 
heat,  or  any  ferro-manganese  added  to  remove  oxygen,  are 
at  once  absorbed  and  distributed  through  the  mass,  and  so 
when  any  serious  irregularity  is  discovered  it  is  charged  to 


A  heat  may  produce  billets  of  75  carbon  and  120  carbon, 
and  again  it  is  called  segregation. 

As  a  rule,  inertia  has  more  to  do  with  such  differences 
than  segregation.  One  crucible  of  steel  may  produce  an 
ingot  containing  90  carbon  and  130  carbon.  Segregation 
has  nothing  to  do  with  this:  a  careless  mixer  has  put  a 
heavy  lump  of  140-  or  150-carbon  steel  in  the  bottom  of  the 
pot  and  covered  it  up  with  iron.  The  steel  melted  first 
and  settled  in  the  bottom  of  the  pot,  the  iron  melted  later 
and  settled  on  top  of  the  steel,  and  they  did  not  mix. 
The  teeming  was  not  sufficient  to  cause  a  thorough  mixing. 

Segregation  covers  a  multitude  of  sins. 

Exactly  how  much  is  sin  and  how  much  is  segregation 
will  not  be  known  until  analyses  are  made  of  the  top,  middle, 
and  bottom  of  the  bath,  and  of  the  contents  of  the  ladle, 
these  to  be  compared  to  analyses  of  the  top,  bottom,  and 
middle  of  the  ingots.  There  is  certainly  an  unavoidable 
amount  of  segregation,  and  as  equally  certain  an  amount 
of  curable  irregularity  due  to  inertia. 


134  STEEL: 


WILD   HEATS. 

After  steel  is  melted,  whether  in  a  crucible,  an  open 
hearth,  or  a  Bessemer  vessel,  it  boils  with  more  or  less  vio- 
lence. This  boiling  is  caused  by  ebullition  of  gases,  and  if 
steel  be  poured  into  moulds  while  it  is  boiling  the  resulting 
ingot  will  be  found  to  be  honeycombed  to  an  extent  that 
is  governed  by  the  degree  of  the  boiling. 

If  a  heat  toils  violently  and  persistently,  it  is  said  to  be 
"wild,"  and  if  a  wild  heat  be  teemed  the  ingots  will  be 
honeycombed  completely;  such  ingots  cannot  be  worked 
into  thoroughly  sound  steel,  and  no  melter  who  has  any  re- 
gard for  his  work  will  teem  a  wild  heat  if  he  knows  it. 

To  stop  the  boiling  is  called  "dead-melting,"  "killing" 
the  steel,  so  that  it  shall  be  quiet  in  the  furnace  and  in 
the  moulds. 

A  crucible-steel  maker  who  knows  his  business  can,  and 
he  will,  always  dead-melt  his  steel.  It  only  requires  a  few 
minutes  of  application  of  a  heat  a  little  above  melting  tem- 
perature, and  this  can  be  applied  by  a  skilled  melter  with- 
out burning  his  crucible  or  cutting  down  his  furnace;  this 
is  indeed  about  all  of  the  art  there  is  in  crucible-melting, 
the  remaining  operations  being  easy  and  simple. 

Dead-melting  in  the  Bessemer  vessel  is  not  possible  by 
increase  of  time;  wild  heats  are  managed  differently,  prob- 
ably by  adding  manganese  or  silicon,  or  both,  but  exactly 
how  is  not  within  the  author's  experience. 

Dead-melting  in  the  open  hearth  would  appear  at  first 
sight  to  be  always  possible,  but  there  are  more  difficulties 
in  the  way  than  in  the  case  of  crucible-melting. 

The  heat  may  be  wild  when  the  right  carbon  is  reached, 


A   MANUAL   FOR   STEEL-USERS.  135 

and  then  the  melter  must  use  a  little  ferro-silicon,  or 
silico-spiegel,  or  highly  silicious  pig,  or  aluminum,  aiid  he 
must  use  good  judgment  so  as  not  to  have  his  steel  over- 
dosed with  any  of  these.  From  half  un  ounce  to  an  ounce 
of  aluminum  to  a  ton  of  steel  is  usually  sufficient,  and  al- 
though any  considerable  content  of  aluminum  is  injurious 
to  steel  there  is  little  danger  of  its  being  added,  because  of 
its  cost,  and  because  a  little  too  much  aluminum  will  cause 
the  ingots  to  pipe  from  top  to  bottom. 

Silicon  seems  to  be  the  most  kindly  element  to  use,  and  it 
is  claimed  that  a  content  of  silicon  as  high  as  20  is  not  inju- 
rious; some  people  claim  that  it  is  beneficial.  That  it  does 
help  materially  in  the  production  of  sound  steel  there  can 
be  no  doubt,  and  if  such  steel  meets  all  of  the  requirements 
of  the  engineer  and  of  practice  it  would  seem  to  be  wise 
not  to  place  the  upper  limit  for  silicon  so  low  as  to  prevent 
its  sufficient  use  in  securing  soundness.  But  the  author 
cannot  concede  that  as  much  as  20  silicon  is  necessary.  In 
crucible  practice  high  silicon  is  not  necessary  ;  in  "melt- 
ing-iron," or  iron  to  be  melted,  it  means  so  much  dirt,  in- 
dicating careless  workmanship;  but  there  will  always  be  a 
little  silicon  present  which  the  steel  has  absorbed  from  the 
walls  of  the  crucible  during  the  operation  of  melting.  In 
high  tool-steel  silicon  should  be  at  the  lowest  minimum 
that  is  attainable. 

This  discussion  of  wild  heats  may  appear  to  be  outside 
of  the  scope  of  this  work,  and  to  belong  exclusively  to  the 
art  of  manufacturing  steel,  of  which  this  book  does  not 
pretend  to  treat.  This  is  true  so  far  that  it  is  not  recom- 
mended that  the  engineer  shall  meddle  in  any  way  with 
the  manufacturer  in  the  management  of  his  work;  on  the 
other  hand,  it  is  vital  to  the  engineer  that  he  should  know 


136  STEEL: 

about  it,  because  wild  steel  may  hammer  or  roll  perfectly 
well,  it  may  appear  to  be  sound,  but  the  author  cannot 
believe  that  it  is  ever  sound  and  reliable. 

Again,  it  has  a  scientific  interest;  that  wilduess  is  due  to 
too  much  gas,  and  probably  to  carbon-gas,  may  be  shown 
by  an  illustration. 

It  has  its  parallel  in  the  rising  of  the  iron  in  a  puddling- 
furnace  at  the  close  of  the  boil,  a  phenomenon  with  which 
every  one  is  familiar  who  has  watched  a  heat  being  boiled 
or  puddled.  That  all  of  the  iron  does  not  run  out  of  the 
puddling-furnace  at  this  stage  is  owing  to  the  fact  that 
there  is  not  heat  enough  in  the  puddling-furnace  to  keep 
the  iron  liquid  after  it  has  been  decarbonized. 

During  the  running  of  a  basic  open-hearth  furnace  an 
apparently  dead  heat  was  tapped;  before  the  steel  reached 
the  ladle  there  was  a  sort  of  explosion;  the  steel  was  blown 
all  over  the  shop,  the  men  had  to  run  for  their  lives,  and 
not  one  tenth  of  the  steel  reached  the  ladle.  The  mana- 
ger was  rated  roundly  for  carelessness  in  not  having  dried 
his  spout,  and  the  incident  closed.  A  few  days  later  an- 
other quiet  heat  was  tapped  and  it  ran  into  the  ladle; 
about  the  time  the  ladle  was  full  the  steel  rose  rapidly, 
like  a  beaten  egg  or  whipped  cream,  and  ran  out  on  to  the 
floor,  cutting  the  sides  of  the  ladle,  the  ladle-chains,  and 
the  crane-beams  as  it  flowed.  The  men  ran,  and  there 
was  no  injury  to  the  person. 

Again  the  manager  was  blamed,  this  time  for  having  a 
damp  ladle,  and  lie  was  notified  of  an  impending  dis- 
missal if  such  a  thing  occurred  again.  He  protested  that 
he  knew  the  ladle  and  the  stopper  were  red-hot,  that  he 
had  examined  them  personally  and  carefully,  and  knew  he 
stated  the  truth. 


A   MANUAL   FOR   STEEL-USERS.  137 

There  were  several  reasons  for  looking  into  the  matter 
farther:  first,  the  man  in  charge  was  known  to  be  truthful 
and  careful,  so  that  there  was  no  reason  for  doubting  his 
word;  second,  if  the  vessel  and  rod  were  red-hot,  there 
could  be  no  aqueous  moisture  there  ;  and,  finally,  such  an 
ebullition  from  dampness  was  contrary  to  experience,  as  a 
small  quantity  of  water  under  a  mass  of  molten  iron,  or 
slag,  results  almost  invariably  in  a  violent  explosion,  like 
that  of  gunpowder  or  dynamite. 

Upon  inquiry  it  was  found  that  prior  to  both  ebullitions 
there  had  been  a  large  hole  in  the  furnace-bottom,  requir- 
ing about  a  peck  of  material  to  fill  it  in  each  case.  Mag- 
nesite  was  used;  the  magnesite  was  bought  raw,  and 
burned  in  the  place.  It  is  well  known  that  it  takes  a  long 
time  and  high  heat  to  drive  carbonic  acid  out  of  mague- 
site,  and  it  was  surmised  that  insufficient  roasting  might 
have  caused  the  trouble.  Samples  of  burned  and  of  raw 
magnesite  were  sent  to  the  laboratory,  and  the  burned  was 
found  to  contain  about  as  much  carbonic  acid  as  the  raw 
magnesite.  Then  the  case  seemed  clear :  This  heavily 
charged  magnesite  was  packed  into  the  hole;  the  heat  was 
charged  and  melted.  The  magnesite  held  the  carbonic  acid 
until  near  the  close  of  the  operation;  then  the  intense  heat 
of  the  steel  forced  the  release  of  the  gas,  which  was  at 
once  absorbed  by  the  steel.  Owing  to  the  superincumbent 
weight  of  the  steel  the  gas  was  absorbed  quietly,  and  when 
the  weight  was  removed  the  gas  escaped,  exactly  as  it  does 
at  the  close  of  puddling  or  in  the  frothing  of  yeast. 

Whether  the  carbonic  acid  remained  such,  or  whether  it 
took  up  an  equivalent  of  carbon  and  became  carbonic 
oxide,  and  then  again  took  up  oxygen  from  the  bath,  and 
so  kept  on  increasing  in  volume,  is  not  knowu 


138  STEEL: 

The  facts  seem  clear,  and  the  collateral  proof  is  that 
thorough  burning  of  the  magnesite,  and  of  any  dolomite 
that  was  used,  prevented  a  recurrence  of  any  such  acci- 
dents. 

Such  ebullitions  have  occurred  and  caused  the  burning 
to  death  of  pitmen,  and  the  statement  of  the  above  case 
may  be  of  use  to  melters  in  the  future  who  have  not  met 
such  an  experience. 

OXYGEN    AND    NITROGEN. 

Oxygen  and  nitrogen  are  present  in  all  steel  aud  both 
are  injurious,  probably  the  most  so  of  all  impurities. 

The  oxides  of  iron  are  too  well  known  to  need  discus- 
sion or  description;  they  are  the  iron  ores  mixed  with 
gangue.  They  are  brittle,  friable,  hard,  and  weak,  like 
sandstones.  Mixed  in  steel  they  can  be  nothing  but  weak- 
ened, elements  of  disintegration.  Let  any  one  take  a 
handful  of  scale — or  rust — oxide  of  iron,  in  his  lingers  and 
crumble  it.  and  it  will  be  difficult  for  him  to  imagine  how 
such  material  could  be  anything  but  harmful  when  incor- 
porated in  steel.  Langley  has  shown,  and  other  scientists 
have  confirmed  him,  that  oxygen  may  exist  in  iron  in  solu- 
tion, and  not  as  oxide:  the  discovery  was  attended  with 
the  assertion  that  such  dissolved  oxygen  produced  exces- 
sive red-shortness.  The  proof  that  red-shortness  was 
caused  in  this  way  was  completed  by  the  removal  of  the 
oxygen  from  some  extremely  red-short  steel;  the  red- 
shortness  disappeared  with  the  oxygen  and  the  steel 
worked  perfectly. 

When  steel  is  melted  very  low  in  carbon,  by  any  process, 
it  is  certain  to  be  red-short  and  rotten  unless  the  greatest 
care  be  used  to  prevent  the  introduction  of  oxygen. 


A  MANUAL   FOB  STEEL-USERS.  139 

Crucible-steel  of  15  carbon  or  less  will  as  a  rule  be  red- 
short  aud  cold-short;  it  will  not  weld,  and  is  generally 
thoroughly  worthless.  The  same  material  melted  to  con- 
tain 18  to  25  carbon  will  be  tough  and  waxlike,  hot  or 
cold.  It  wil/  weld  easily  into  tubes,  and  may  be  stamped 
cold  into  almost  any  desired  shape. 

Bessemer  or  open-hearth  steel  of  less  than  8  carbon  is 
almost  certaiu  to  be  equally  worthless,  whereas  the  same 
material  blown  or  melted  not  below  10  or  12  carbon,  and 
re-carbonized  not  above  20,  will  be  tough  and  good  at  any 
heat  under  granulation,  and  equally  good  and  tough  when 
cold. 

As  to  Bessemer  steel,  the  author  cannot  say  whether  it 
would  be  possible  to  stop  the  blow  between  10  and  15 
carbon  or  not,  but  it  seems  certain  that  if  there  be  no 
overblowing  red-shortness  and  cold-shortness  may  be 
avoided  by  carbonizing  back  to  about  15  by  the  use  of 
manganese  or  silicon,  or  both  together. 

In  the  open  hearth  it  is  always  possible  to  stop  the 
melt  at  10  carbon,  and  to  deoxidize  the  heat  so  as  to  avoid 
shortness,  and  not  to  go  above  20  carbon.  Such  steel  will 
be  sound  and  tough ;  it  will  weld  and  stamp  perfectly,  and 
will  be  satisfactory  for  all  reasonable  requirements. 

The  reason  of  this  seems  to  be  simple  and  plain :  In 
melting  or  blowing  out  the  last  fractions  of  carbon  below 
10  to  15  the  same  quantity  of  air  per  second  or  minute 
must  be  used  as  when  burning  out  the  higher  quantities, 
and  now  there  is  so  little  carbon  to  be  attacked  that  the 
oxygen  necessarily  attacks  the  iron  in  greater  and  greater 
force  as  the  carbon  decreases. 

This  leaves  an  excess  of  oxygen  in  the  steel  which  cannot 


140  STEEL: 

be  removed  by  the  ordinary  quantities  of  silicon,  or  man- 
ganese, or  aluminum. 

If  more  manganese  or  silicon  be  used,  the  red-shortness 
and  weakness  can  be  cured  largely;  but  then  the  carbon 
is  raised  considerably,  and  thus  the  steel  is  brought  up  to 
where  it  would  have  been  without  this  excessive  Decar- 
bonizing, with  the  difference  that  it  is  not  quite  so  strong. 

What  good  is  there,  then,  in  extremely  low  melting? 

It  must  be  admitted  that  there  are  tough,  good-working 
steels  in  the  market  of  carbon  <  5,  manganese  <  20.  They 
are  made  in  small  furnaces,  worked  with  great  care;  the 
product  is  expensive,  and,  unless  it  is  wanted  to  be  welded 
in  place  of  common  wrought  iron,  it  is  in  no  case  as  good 
as  well-made  steel  of  12  to  20  carbon;  even  for  welding 
the  latter  is  superior  if  the  worker  will  only  be  satisfied  to 
work  at  a  lemon  instead  of  a  scintillating  heat. 

These  special  cases  do  not  militate  against  the  general 
fact  that  extremely  low  steel  is  usually  red-short  and  weak. 

The  above  is  written  for  the  consideration  of  those  en- 
gineers who  think  they  are  going  safe  when  they  prescribe 
low  tensile  strength  and  excessive  ductility.  If  these 
requirements  meant  the  reception  of  pure,  or  nearly  pure, 
iron,  indicated  by  the  low  tenacity  and  high  stretch,  then 
they  would  be  wise;  but  if  they  result,  as  they  almost  cer- 
tainly do,  in  initially  good  material  rotted  by  overdoses  of 
oxygen  the  wisdom  may  not  be  so  apparent. 

NITROGEN. 

The  real  influence  of  nitrogen  is  not  known  to  the  author. 
Percy  shows  that  nitrogenized  iron  is  hard,  exceedingly 
friable,  and  causes  a  brilliant,  brassy  lustre.  He  also  siiys 
nitrogen  is  driven  out  at  a  yellow  heat;  doubtless  this  is 


A   MANUAL   FOR   STEEL-USERS.  141 

true  of  the  excess  of  nitrogen,  but  it  has  been  shown  in 
Chapter  II  that  melting  in  a  crucible  will  not  drive  the 
nitrogen  out  of  Bessemer  steel. 

When  crucible-steel  not  made  from  Bessemer  scrap  and 
Bessemer  steel  of  equal  analysis  are  compared  in  the  tem- 
pered condition,  there  is  almost  invariably  a  yellowish  tinge 
over  the  fresh  Bessemer  fracture  which  distinguishes  it 
from  the  crucible-steel.  The  Bessemer  steel  is  also  the 
weaker.  These  differences  are  believed  to  be  due  to  nitro- 
gen. 

Langley  maintains  his  belief  that  oxygen  is  still  the  chief 
mischief-maker:  the  author  believes  nitrogen  to  be  the 
more  potent  of  the  two;  there  is  no  known  way  to  remove 
the  nitrogen,  and  there  the  question  stands. 

ELEMENTS   OF   DISINTEGRATION. 

It  has  been  stated  time  and  again  that  these  impurities 
are  elements  of  disintegration,  and  that  it  would  be  wise  in 
every  case  to  restrict  the  quantities  allowable  within  rea- 
sonable limits,  giving  the  steel-maker  sufficient  leeway  to 
enable  him  to  work  efficiently  and  economically,  and  at  the 
same  time  to  keep  the  quantities  of  these  impurities  as  low 
as  possible. 

On  the  other  hand,  able,  successful,  and  conservative 
engineers  have  claimed  that  if  the  steel-maker  meets  their 
physical  requirements  as  shown  by  prescribed  tests  they, 
the  engineers,  should  be  satisfied;  that  they  should  not 
interfere  with  chemical  composition,  as  they  had  no  fear  of 
subsequent  disintegrations. 

This  argument  was  answered  by  the  statement  that 
skilled  steel-workers  could  manipulate  poor  steel  so  as  to 
bring  it  up  to  the  requirements;  that  the  well-trained 


142  STEEL: 

workers  in  the  bridge-shops  would  not  abuse  the  steel;  that 
the  inherent  deficiencies  would  not  be  developed ;  the  work 
would  go  out  apparently  satisfactory;  and  that  it  might  re- 
main so  for  a  long  time,  in  the  absence  of  unusual  shocks 
or  strains,  but  that  in  an  emergency  such  material  might 
fail  because  of  deterioration  where  a  purer  material  would 
have  held  on.  In  the  absence  of  proofs  such  statements 
have  been  met  with  a  smile  of  incredulity. 

Fortunately  some  proofs  are  now  at  hand,  and  as  the 
method  of  getting  them  has  been  obtained,  more  will  follow 
from  time  to  time. 

In  Engineering,  Jan.  17,  1896,  Mr.  Thomas  Andrews, 
F.R.S.,  M.Inst.C.E.,  gives  the  following  cases: 

A  fracture  of  a  rail  into  many  pieces,  causing  a  serious 
accident. 

A  broken  propeller-shaft  which  nearly  caused  a  disastrous 
accident. 

Analysis  of  the  rail: 

Carbon 0.440 

Silicon 0.040 

Manganese 0.800 

Sulphur 0.100 

Phosphorus 0.064 

It  is  clear  that  the  sulphur  is  excessive,  and  that  it  was 
neutralized  so  as  to  make  the  steel  workable  by  an  excess 
of  manganese. 

Of  the  propeller-shaft  Mr.  Andrews  says  chemical  analy- 
sis of  outside  and  central  portions  of  the  shaft  showed 
serious  segregation. 

"The  percentage  of  combined  carbon  was  nearly  50  per 
cent  greater  in  the  inside  of  the  shaft  than  on  the  out- 


A  MANUAL   FOR  STEEL-USERS.  143 

side;  the  manganese  was  also  in  excess  in  the  inside  of  the 
shaft;  the  phosphorus  and  sulphur  had  also  segregated  in 
the  interior  of  the  shaft  to  nearly  three  times  the  percent- 
age of  these  elements  found  near  the  outside  of  the  shaft." 

Unfortunately  Mr.  Andrews  does  not  give  the  analysis  of 
the  shaft. 

A  number  of  micro-sections  of  the  rail  and  of  the  shaft 
were  made  and  examined. 

"Numerous  micro-sulphur  flaws  were  found,  varying  in 
size  from  0.015  inch  downward,  interspersed  or  segregated 
in  the  intercrystalline  junctions  of  the  ultimate  crystals  of 
the  steel,  and  being  located  in  such  a  manner  as  to  prevent 
metallic  cohesion  between  the  facets  of  the  crystals,  thus 
inducing  lines  of  internal  weakness  liable  to  be  acted  upon 
by  the  stress  and  strain  of  actual  wear." 

The  dimensions  of  these  flaws  in  the  rail  varied  from 
.0150  X  .0012  to  .0010  X  .0004  parts  of  an  inch. 

In  the  shaft  from  .0160  X  .0030  to  .0020  X  .0016  parts 
of  an  inch. 

In  the  rail  he  found  as  many  as  14  flaws  in  an  area  of 
only  0.00018  square  inch,  equal  to  nearly  60,000  flaws  per 
square  inch. 

In  the  shaft  he  found  as  many  as  34  flaws  in  an  area  of 
only  0.00018  square  inch,  equal  to  nearly  190,000  per 
square  inch. 

In  speaking  of  the  shaft  he  says:  "In  addition  to 
blow-holes,  air-cavities,  etc.,  the  interior  of  the  shaft  was 
literally  honeycombed  with  micro-sulphide  of  iron  flaws, 
which  were  meshed  about  and  around  the  primary  crystals 
of  the  metal  in  every  direction."  "  The  deleterious  effects 
of  an  excess  of  manganese  in  interfering  with  the  normal 


144  STEEL: 

crystallization  of  the  normal  carbide  of  iron  ureas  were 
also  perceptible." 

As  the  number  of  micro-sulphur  flaws  in  the  shaft  were 
about  three  times  as  many  as  in  the  rail,  we  may  assume 
that  the  shaft  contained  at  least  as  large  a  percentage  of 
sulphur  as  the  rail,  and,  owing  to  the  general  honey- 
combed structure,  it  would  not  be  a  far  guess  to  assume 
that  the  steel  was  teemed  wild. 

"  The  deleterious  effect  of  these  treacherous  sulphur  areas 
and  other  microscopic  flaws,  with  their  prolonged  ramifica- 
tions spreading  along  the  intercrystalline  spaces  of  the 
ultimate  crystals  of  the  metal  and  destroying  metallic  co- 
hesion, will  be  easily  understood." 

"  Constant  vibration  gradually  loosens  the  metallic  ad- 
herence of  the  crystals,  especially  in  areas  where  these 
micro  flaws  exist.  Cankering  by  internal  corrosion  and 
disintegration  is  induced  whenever  the  terminations  of  any 
of  the  sulphide  areas  or  other  flaws  in  any  way  become 
exposed  at  the  surface  of  the  metal,  either  to  the  action  of 
sea-water,  or  atmospheric  or  other  oxidizing  influences. 
In  many  other  ways,  also,  it  will  be  seen  how  deleterious  is 
their  presence." 

"Internal  micro-flaws  of  various  character  are  neverthe- 
less almost  invariably  present  in  masses  of  steel,  and  consti- 
tute sources  of  initial  weakness  which  not  unfrequently  pro- 
duce those  mysterious  and  sudden  fractures  of  steel  axles, 
rails,  tires,  and  shafts  productive  of  such  calamitous  results. 
A  fracture  once  commencing  at  one  of  these  micro-flaws 
(started  probably  by  some  sudden  shock  or  vibration,  or 
owing  to  the  deterioration  caused  by  fatigue  in  the  metal) 
runs  straight  through  a  steel  forging  on  the  line  of  least 


A   MANUAL   FOR   STEEL-USERS.  145 

resistance,-  in  a  similar  manner  to  the  fracture  of  glass  or 
ice." 

It  is  understood  that  similar  investigations  are  being 
carried  out  on  an  extensive  scale  by  Prof.  Arnold;  in  the 
meantime  the  above  cases  should  satisfy  any  one  that  these 
impurities  are  elements  of  disintegration,  and  that  the  less 
there  are  of  them  in  any  steel  the  better  for  the  steel. 

It  seems  clear  that  if  10  sulphur  will  cause  60,000  flaws 
per  square  inch,  01  sulphur  ought  not  to  cause  more  than 
one  tenth  of  that  number;  or,  if  an  equal  number,  then 
they  could  only  be  one  tenth  of  the  size. 

The  segregation  found  in  the  shaft  is  so  excessive  that  it 
would  seen  probable  that  there  was  a  good  deal  of  sin  there 
also;  but,  even  if  it  were  unavoidable  segregation,  the  harm 
would  have  been  just  so  much  the  less  if  there  had  been 
less  of  total  impurities  present  to  segregate. 

ARSENIC. 

Arsenic  is  known  to  be  very  harmful  in  tool-steel,  and  it 
is  proper  to  assume  that  it  can  do  no  good  in  structural 
steel.  Ill  any  case  where  the  properties  of  steel  do  not 
come  up  to  the  standard  to  be  expected  from  the  regular 
analysis  examination  should  be  made  for  arsenic,  antimony, 
copper,  etc.  These  are  not  as  universal  constitutents  of 
steel  as  silicon,  phosphorus,  sulphur,  and  manganese,  but 
they  are  present  frequently,  and  in  any  appreciable  amount 
they  are  bad. 


146  STEEL: 


XI. 

THEORIES  OF  HARDENING. 

THE  hardening  of  steel  is  such  a  marked  phenomenon, 
and  one  of  so  great  importance,  that  it  has  always  attracted 
a  great  deal  of  attention,  and  many  theories  have  been  put 
forward  in  explanation. 

Before  chemistry  was  brought  to  bear  upon  the  subject 
the  proposed  theories  were  based  upon  assumption,  and  as 
there  were  no  proofs  one  had  as  much  right  to  consideration 
as  another,  and  none  seemed  to  be  altogether  satisfactory. 

Since  science  has  taken  up  the  question  the  theories  are 
about  as  numerous  as  the  investigators,  and  while  no  one 
can  claim  as  yet  to  have  settled  the  matter  definitely,  each 
one  has  an  apparent  basis  of  reason  deduced  from  observed 
facts. 

Among  early  observations  it  was  noted  that  when  un- 
hardened  steel  and  hardened  steel  were  dissolved  in  acid 
a  much  larger  amount  of  carbon  was  found  in  the  solu- 
tion of  the  unhardened  than  in  that  of  the  hardened 
steel.  This  led,  first,  to  the  distinction  of  combined  carbon 
and  graphitic  carbon,  a  distinction  that  has  been  main- 
tained through  subsequent  investigations.  It  seems  to  be 
well  established  now  that  there  is  a  definite  carbide  of  iron, 
Fe,C,  and  some  observers  believe  it  to  be  the  hard  sub- 
stance in  hardened  steel. 

Following  this  came  the  announcement  that  these  condi- 


A   MANUAL   FOR  STEEL-USERS.  14? 

tions,  combined  and  graphitic  carbon,  represented  two 
different  forms  of  carboii,  and  they  were  designated  as 
cement  carbon  and  hardening  carbon;  also  as  non-harden- 
ing and  hardening  carbon.  Later  investigation  having 
established  the  existence  of  the  carbide  Fe3C,  this  was 
claimed  to  be  the  hard  body,  but  this  has  not  met  universal 
acceptance. 

Another  investigator,  studying  by  means  of  the  py- 
rometer and  observing  heat  phenomena,  concludes  that 
hardening  is  due  to  an  allotropic  condition  of  the  iron 
itself;  that  when  iron  is  heated  above  the  recalescent-point, 
and  presumably  below  granulation,  it  becomes  in  itself 
excessively  hard;  that  sudden  cooling  prevents  its  changing 
from  this  form,  and  so,  when  there  is  carbon  present,  the 
result  of  quenching  is  great  hardness. 

When  steel  is  allowed  to  cool  slowly  to  below  recalescence, 
the  iron  assumes  another  form,  and  one  which  cannot  be 
hardened  by  quenching;  this  latter  is  known  as  a  iron,  and 
the  hardening  kind  as  ft  iron.  A  later  investigator  finds  it 
necessary  to  have  a  third  allotropic  form  to  meet  some  of 
the  phenomena,  which  he  designates  by  another  Greek 
letter. 

Another  investigator  establishes  independently  the  satu- 
ration-point, which  was  pointed  out  and  published  twenty 
years  ago,  viz ,  somewhere  about  90  to  100  carbon;  he  fixes 
the  saturation- point  at  89  carbon  and  gives  the  formula 
Fe,4C.  He  assumes  that  this  is  an  exceedingly  unstable 
carbide,  that  it  is  formed  between  recalescence  and  granu- 
lation, and  can  only  be  fixed  by  quenching,  and  that  when 
steel  is  quenched  the  fixing  of  this  carbide  is  the  cause  of 
hardness. 

A  still  later  investigation  establishes  this  saturation-point 


148  STEEL: 

at  about  100  carbon  by  observing  that  in  hardened  steel  of 
135  carbon  there  is  a  combination  of  100  carbon  which  is 
the  excessively  hard  part  of  the  steel,  and  a  portion  con- 
taining the  remaining  35  parts  of  carbon  that  is  not  quite 
so  hard,  and  he  suggests  a  fourth  allotropic  form  to  cover 
this  part. 

It  is  also  suggested  that  steel  should  be  considered  and 
treated  as  an  igneous  rock;  judging  from  the  appearance  of 
magnified  micro-sections,  this  suggestion  appears  to  be  a 
happy  one  for  the  purpose  of  making  comparisons. 

The  above  theories  of  hardening,  and  others,  are  not  to 
be  regarded  as  antagonistic  or  contradictory,  doubtless  there 
are  germs  of  truth  in  every  one  of  them,  or  each  one  may 
be  merely  the  individual's  way  of  suggesting  an  explanation 
of  the  same  observed  phenomena,  so  that  when  a  final  con- 
clusion is  reached  each  may  be  found  to  have  been  travel- 
ling in  the  same  direction  by  a  different  path.  It  is  certain 
that  able,  patient,  painstaking,  men  are  working  faithfully 
to  produce  a  solution  of  the  problem,  and  even  if  their 
ideas,  as  briefly  given  above,  do  seem  to  be  contradictory  it 
would  only  evince  deeper  ignorance  and  a  stupid  mind  in 
any  who  should  attempt  to  ridicule  or  unduly  criticise 
honest  work  before  it  is  completed.  While  these  investig;i- 
tions  are  going  on,  and  before  any  definite  conclusion  is 
reached,  is  there  any  well-established  safe  ground  for  the 
steel-worker  and  the  engineer  to  stand  upon  ?  There  cer- 
tainly is  a  good  working  hypothesis  for  all  to  use,  and  one 
which  it  is  believed  will  always  be  the  right  one  to  follow 
no  matter  what  the  final  explanation  of  the  remarkable 
phenomena  of  hardening,  tempering,  and  annealing  may 
prove  to  be. 

After  many  years  of  careful  experimenting  and  study 


A  MANUAL  FOR  STEEL-USERS.  149 

Prof.  J.  W.  Langley  came  to  the  conclusion  that  no  matter 
what  the  final  result  might  be  as  to  carbides,  allotropic  con- 
ditions, etc.,  that  if  steel  were  considered  as  iron  containing 
carbon  in  solution,  whether  it  were  a  chemical  combination 
or  a  mere  solution,  and  that  cold  steel  be  regarded  as  a 
congealed  liquid  in  a  state  of  tension,  then  all  known 
phenomena  could  be  accounted  for,  and  all  known  condi- 
tions could  be  produced  with  certainty  by  well-known  ap- 
plications of  heat  and  force. 

When  carbon  is  in  the  so-called  combined  condition, 
then  the  solution  may  be  compared  to  pure  sea-water;  when 
the  carbon  is  partly  combined  and  partly  graphitic,  the 
solution  may  be  compared  to  muddy  sea- water,  the  mud 
representing  the  graphitic  carbon. 

When  the  carbon  is  practically  all  graphitic,  as  in  over- 
annealed  steel,  then  the  solution  may  be  compared  to  thor- 
oughly muddy  fresh  water. 

This  hypothesis  of  solution  agrees  well  with  the  saturation 
noted;  then  about  100  carbon  is  all  that  iron  will  dissolve 
without  extraneous  force;  and  higher  carbon  must  be  forced 
into  solution  by  the  work  of  hammers,  presses,  or  rolls. 

This  gives  reason  to  the  experienced  tool-maker's  well- 
known  preference  for  well-hammered  steel. 

The  hypothesis  of  tension,  probably  molecular,  covers  all 
of  the  phenomena  of  excessive  hardness  due  to  high  heat, 
which  means  high  molecular  motion  checked  violently  by 
sudden  quenching.  It  accounts  for  the  progressive  soften- 
ing due  to  every  added  degree  of  heat,  and  it  accounts  for 
rupture,  cracking,  due  to  excessive  heat  or  to  any  uneven- 
ness  of  heat. 

Without  this  hypothesis  of  tension  it  is  difficult  to  un- 
derstand why  quenching  should  rupture  a  piece  of  steel,  no 
matter  what  the  degree  of  heat,  or  how  uneven  it  might  be. 


150  STEEL: 

Without  it,  too,  it  is  hard  to  see  how  successive  additions 
of  heat  can  cause  gradual  changes  from  ft  to  a  iron,  or 
from  an  unstable  carbide  to  an  imperfect  solution.  It 
would  seem  that  the  allotropic  changes,  or  the  decomposi- 
tions of  carbides,  must  be  more  marked  than  the  gradual 
changes  from  hard  to  soft  which  we  know  to  take  place  by 
slow  and  gentle  accretions  of  heat. 

There  is  no  property  of  steel  known  to  the  author  which 
is  not  covered  by  Langley's  hypothesis,  and  therefore  it  is 
put  forward  with  confidence  for  engineers  and  steel-users 
to  work  by  until  the  scientists  shall  have  completed  their 
investigations,  and  after  that  it  is  believed  that  it  will  be  a 
safe  working  hypothesis,  because  science  does  not  change 
facts,  it  only  collates  them  and  reveals  the  laws  of  action. 

Under  this  hypothesis  of  Langley's  we  may  define  hard- 
ness as  tension,  softness  as  absence  of  tension. 

This  is  not  stated  as  established  fact;  it  is  given  as  a 
simple  definition  to  cover  the  known  phenomena  until  the 
final  solution  of  the  problem  shall  lead  to  a  better  explana- 
tion. 

Regarding  steel  as  a  solution  of  carbon  in  iron,  one  im- 
portant fact  may  be  set  down  as  established  thoroughly: 
that  is,  that  the  more  perfect  the  solution  under  all  circum- 
stances the  better  the  steel. 

Continued  application  of  heat  in  any  part  of  the  plastic 
condition  allows  carbon  to  separate  out  of  solution  into  a 
condition  of  mere  mixture;  it  converts  the  clear  sea- water 
into  muddy  water;  this  is  the  reason  why  so  much  em- 
phasis has  been  given  in  previous  chapters  to  the  harmful- 
ness  of  long-continued  heating. 

In  every  case,  when  steel  is  hot  enough  for  the  purpose 
desired,  it  should  be  removed  at  once  from  the  fire. 


A  MANUAL  FOR  STEEL-USERS.  151 


XII. 

INSPECTION. 

CAREFUL  and  systematic  inspection  is  of  the  utmost  im- 
portance from  the  first  operation  of  melting  to  the  last  act 
of  the  finisher. 

Assuming  that  every  operator  is  honest  and  conscien- 
tious in  the  performance  of  Ms  work,  the  personal  equation 
must  be  considered,  as  well  as  the  exigencies  of  the  many 
operations.  The  steel-maker  must  inspect  his  ingots  to  see 
that  they  are  melted  well  and  teemed  properly,  that  they 
are  sound  and  clean,  and  to  determine  their  proper  temper. 

When  work  is  finished,  he  must  inspect  it  to  see  that  it 
has  been  worked  at  proper,  even  heats,  that  it  is  correct  in 
dimensions,  and  that  all  pipes  and  seams  have  been  cut  out. 
After  all  this  has  been  done  faithfully  it  were  well  that  his 
work  were  done  when  it  were  well  done.  Such  is  not  his 
happy  lot;  every  successive  manipulator  may  ruin  the  steel 
by  carelessness  or  ignorance,  and  it  is  a  gala  day  for  a  steel- 
maker when  lie  does  not  receive  some  sample  of  stupid  ig- 
norance or  gross  carelessness,  with  an  intimation  that  it 
would  be  well  for  him  to  learn  how  to  make  steel  before  he 
presumed  to  offend  by  sending  out  such  worthless  material. 
And  sometimes,  though  not  so  often  if  he  knows  his  busi- 
ness, he  finds  a  complaint  well  founded;  then  he  must  regu- 
late his  own  household  and  make  his  peace  with  his  angry 
customer  as  best  he  can. 

The  engineer  must  inspect  his  steel  to  see  that  it  is 
sound,  and  clean,  and  finished  properly,  as  he  has  a  right 
to  expect  that  it  should  be. 


152  STEEL' 

It  is  not  intended  here  to  lay  down  rules  for  shop  and 
field  inspection, — that  is  an  art  in  itself  outside  of  the  func- 
tion or  the  experience  of  a  steel-maker, — but  some  hints  may 
be  given  as  to  the  examination  of  steel  as  it  comes  from  the 
mill,  and  it  has  been  the  aim  in  previous  chapters  to  give 
such  information  as  may  enable  an  engineer  to  form  a  good 
judgment  as  to  matters  which  are  not  likely  to  come  to  his 
knowledge  in  the  course  of  ordinary  practice. 

Steel  should  be  sound;  it  should  be  examined  before  it  is 
oiled  or  painted.  All  pipe  should  be  cut  off;  a  pipe  of  any 
considerable  size  will  show  in  the  end  of  a  sheared  bar,  and 
a  careful  observer  will  soon  learn  to  detect  it.  If  there  is 
reason  to  suspect  a  pipe,  file  the  place  and  the  pipe  will  be 
revealed  if  it  is  there.  Do  not  chip  at  it,  for  a  chisel  will 
often  smooth  a  line  which  a  file  will  bring  out.  In  tool- 
steel  there  should  not  only  be  no  pipe,  there  should  be  no 
star  left  in  the  bar.  A  "  star "  is  a  bright  spot  which 
shows  the  last  of  the  pipe,  not  quite  cut  away;  the  steel  is 
not  solid  in  the  star  and  it  will  not  make  a  good  cutting- 
edge;  it  may  even  cause  a  sledge  to  split. 

SEAMS. 

In  tool-steel  there  should  be  no  seams  at  all.  Some  makers 
declare  that  in  high  steel,  seams  are  evidences  of  good 
quality;  such  a  statement  is  the  veriest  fraud;  it  is  hard  to 
get  any  high  steel  free  from  seams,  and  therefore  if  the 
maker  can  get  the  user  to  believe  that  a  seam  is  a  good 
thing  he  can  enhance  his  profit;  that  is,  he  can  enhance  it 
for  a  time  until  his  fraud  is  understood. 

Some  seams  are  hard  to  see;  when  there  is  reason  to  sus- 
pect one,  a  little  filing  across  the  line  will  show  it  in  a  dis- 
tinct black  line  if  it  is  there.  A  file  is  an  indispensable 
tool  for  an  inspector,  better  than  a  chisel  or  a  grindstone. 


A   MANUAL   FOR  STEEL-USERS.  153 

lu  machinery  and  structural  steel  a  few  small  seams 
may  be  unobjectionable;  too  close  inspection  may  lead  to 
unnecessary  cost  without  a  compensating  gain;  still  every 
engineer  should  reserve  the  right  to  determine  what  seams 
are  allowable  and  what  are  not,  for  his  own  safety. 

Lops  should  not  be  tolerated  in  any  work. 

Torn  cracks  on  edges  or  surface  indicate  burned  steel 
or  red  short  steel;  they  should  not  be  allowed. 

The  grain  of  steel  should  be  practically  uniform,  not  too 
coarse,  not  with  brilliant  lustre,  nor  with  a  dark  india-ink 
tint.  With  an  even  fine  grain,  a  bright  lustre  may  indicate 
a  mild  steel  not  worked  badly.  Inspectors  must  learn  by 
practice  what  is  tolerable  and  what  is  not,  as  it  is  impossi- 
ble to  lay  down  hard  and  fast  rules;  it  is  safe,  however,  to 
say  that  a  fairly  fine  grain  of  even  texture,  not  much  lustre, 
and  no  iudia-ink  shade,  is  indicative  of  good  heating  and 
proper  working. 

With  these  few  general  hints  the  subject  must  be  left, 
for,  like  tempering,  inspecting  is  an  art  in  itself,  and  it  can- 
not be  taught  in  a  book. 

An  expert  inspector  will  see  seams  and  pipes  with  his 
naked  eye  that  a  novice  could  not  detect  with  an  ordinary 
m  agn  i  f y  i  n  g-gl  ass . 

It  may  do  no  harm  to  the  inspector  to  suggest  to  him 
that  amiability  and  good  sense  are  the  best  ingredients  to 
mix  with  sound  judgment. 

If  he  will  cultivate  these,  and  learn  to  distinguish  be- 
tween a  mere  blemish  and  a  real  defect,  he  will  find  his 
work  made  easy  and  pleasant;  and  he  will  be  far  less  likely 
to  have  bad  work  thrust  at  him  than  he  will  if  he  makes  it 
apparent  that  he  regards  himself  as  the  only  honest  man. 


154  STEEL: 


XIII. 

SPECIFICATIONS. 

SPECIFICATIONS  should  cover  three  principal  points: 

Physical  properties:  Elastic  limit;  ultimate  tensile 
strength;  elongation;  reduction  of  area. 

Chemical  constituents:  Limiting  silicon,  phosphorus, 
sulphur,  manganese,  and  copper;  all  other  elements  to  be 
absent  or  .mere  traces  in  quantity,  except  carbon. 

Finish  and  general  condition:  Fixing  limit  of  variation 
in  size  from  a  given  standard:  conditions  as  to  pipes, 
seams,  laps,  uniformity  of  grain,  and  other  defects;  no 
red-shortness. 

PHYSICAL  PROPERTIES. 

It  has  been  shown  in  Chap.  V  that  tensile  strength  may 
be  had  from  46,800  Ibs.  per  square  inch  to  248,700  Ibs.  per 
square  inch. 

There  are  published  in  many  transactions  and  technical 
periodicals  thousands  of  tests  giving  elastic  and  ultimate 
strength,  ductility,  etc.,  so  that  every  engineer  can  find 
easily  what  has  been  done  to  guide  him  as  to  what  he  can 
get. 

In  almost  every  case  the  engineer  must  be  the  judge  as 
to  the  requirements  in  each;  therefore  it  would  be  useless 
to  attempt  to  lay  down  any  fixed  rules  or  limits. 

Many  engineers  adhere  to  low  tenacity  and  high  ductility 


A   MANUAL   FOR   STEEL-USERS.  155 

in  the  belief  that  they  are  securing  that  material  which 
will  be  safest  against  suddeii  shocks  and  violent  accidental 
strains. 

Theoretically  this  appears  to  be  correct,  but  if  the  state- 
ments made  in  the  preceding  chapters  are  credible  it  is 
plain  that  the  limit  to  such  safety  can  be  passed,  and  that 
in  insisting  upon  too  low  tenacity  and  high  ductility  the 
engineer  may  be  getting  simply  a  rotten,  microscopically 
unsound  material,  through  no  fault  of  the  manufacturer, 
who  has  been  compelled  to  overmelt  or  overblow  his  steel 
to  meet  the  requirements,  and  so  reducing  the  quality  of 
otherwise  good  material  at  no  saving  in  cost  to  himself,  and 
at  a  considerable  cost  in  quality  to  the  consumer. 

Any  manufacturer  would  rather  check  his  melt  between 
10  and  15  carbon,  or  stop  his  blow  so  as  to  be  sure  not  to 
overblow,  if  he  were  asked  to  do  so,  because  it  would  save 
him  time  and  expense,  and  it  would  yield  sounder,  better, 
and  easier  working  steel. 

It  may  not  be  wise  yet  for  an  engineer  to  fix  limits  as 
to  blowing  or  melting,  for  the  reason  that  neither  he  nor 
his  assistants  would  know  how  to  insure  compliance,  and 
in  attempting  to  do  it  they  might  interfere  too  far  with 
manufacturing  operations  and  so  involve  themselves  in 
responsibilities  which  they  ought  not  to  assume. 

On  the  other  hand,  if  they  will  let  the  carbon  and  tensile 
strength  run  up  a  little  and  reduce  ductility  slightly,  it  is 
safe  to  say  that  any  manufacturer  will  be  glad  of  the  chance 
to  help  them  to  get  the  best  results,  which  involve  no  extra 
cost. 

Boiler-steel  and  rivet-steel  usually  suffer  the  most  in  this 
respect.  A  boiler  should  be  tough,  yet  it  is  the  belief  of 
the  author  that  boilers  made  of  the  40,800-lb.  steel  of 


156  STEEL: 

which  the  analysis  is  given  in  Chap.  V  would  not  last  half 
as  long  as  boilers  made  of  G5,000-lb.  to  70,000-lb.  steel 
when  the  increased  strength  was  gained  by  added  carbon 
and  no  overmelting  was  allowed. 

In  the  same  table  the  "  Crucible-sheet "  column  gives  a 
mean  of  '24  tests,  and  a  mean  analysis,  of  boiler-steel  which 
has  been  in  use  in  12  boilers  for  nearly  16  years.  The 
boilers  are  in  perfectly  good  condition;  they  have  been  sub- 
jected to  severe  and  very  irregular  usage,  and  they  have 
been  in  every  way  satisfactory,  Only  one  test-piece  of  the 
24  was  mild  enough  to  stand  the  ordinary  bending  test 
after  quenching. 

That  46,800-lb.  steel  is  remarkably  pure  chemically;  it 
is  unusually  red-short.  It  would  appear  to  some  to  be  an 
ideal  rivet-steel ;  it  would  stand  a  very  high  heat,  it  would 
head  well  and  finish  beautifully  under  a  button-set.  There 
is  every  probability  that  the  majority  of  rivets  driven  of 
that  steel  would  be  cracked  on  the  under  side  of  the  head, 
where  the  cracks  would  never  be  discovered  until  in  service 
the  heads  flew  off. 

Kails  are  usually  made  of  40  to  45  carbon,  tires  from  65 
up  to  80  carbon,  crank-pins  as  high  as  70  carbon,  with 
85,000  Ibs.  to  95,000  Ibs.  tensile  strength  and  12#  to  15# 
elongation. 

It  is  difficult  to  see  how  a  bridge  or  a  boiler  is  to  be 
subjected  to  any  such  violent  usage  as  these  receive  daily; 
and  while  it  is  not  advised  that  even  40  carbon  should  be 
used  in  boilers  or  bridges,  although  it  would  be  perfectly 
safe,  it  does  seem  to  be  unreasonable  to  run  to  the  other 
extreme  to  the  injury  of  the  material. 

For  steel  for  springs,  and  for  all  sorts  of  tools  that  are  to 


A   MANUAL  FOR   STEEL-USERS.  157 

be  tempered,  there  is  no  need  of  a  specification  of  physical 
properties  as  they  are  indicated  by  testing-machines. 

The  requirement  that  they  shall  harden  safely  and  do 
good  work  afterwards  involves  necessarily,  high  steel  of 
suitable  quality. 

CHEMICAL   CONSTITUENTS. 

No  engineer  should,  unless  he  be  an  expert  steel-maker, 
attempt  to  specify  an  exact  chemical  formula  and  a  corre- 
sponding physical  requirement;  in  doing  so  he  would  prob- 
ably make  two  requirements  which  could  not  be  obtained 
in  one  piece  of  steel,  and  so  subject  himself  to  a  back  down 
or  to  ridicule,  or  both. 

On  the  other  hand,  he  may  properly,  and  he  should  fix, 
a  limit  beyond  which  the  hurtful  elements  would  not  be 
tolerated.  Notwithstanding  satisfactory  machine  tests, 
successful  shop-work,  and  a  liberal  margin  of  safety,  no 
steel  can  be  relied  upon  that  is  overloaded  with  phosphorus, 
sulphur,  manganese,  oxygen,  antimony,  arsenic,  or  nitrogen. 
In  regard  to  silicon,  it  is  common  to  have  as  much  as  20 
to  25  points  in  tire,  with  55  to  80  carbon  ;  such  tires  are 
made  by  the  best  manufacturers,  and  they  endure  well. 
Hut  it  is  certain  that  good,  sound  steel  can  be  made  for  any 
purpose  with  silicon  not  exceeding  10. 

Structural  steel  can  be  made  cheaply  within  the  follow- 
ing limits: 

Silicon <  .10 

Phosphorus. <  .05 

Sulphur <.02 

Manganese <  .50  or  even  <  .30 

Copper <  .03 

Carbon  to  meet  the  physical  requirements 


158  STEEL: 

Steel  made  within  these  limits  and  not  overblown  or 
overmelted  must  be  better  in  every  way  than  steel  of 

Silicon >  .20 

Phosphorus >  .08 

Sulphur >  .05 

Manganese >  .60 

Carbon  to  meet  the  same  requirements 

A  steel  of  the  latter  composition,  or  with  no  fixed  limits, 
may  be  made  cheaper  than  the  first  by  a  dollar  or  two  A 
ton  ;  but  for  any  large  lot  it  is  believed  that  the  first  speci- 
fication would  be  bid  to  at  as  low  a  price  as  if  there  were 
no  specification;  competition  among  manufacturers  would 
fix  that.  At  any  rate  there  is  no  reason  why  an  engineer 
should  refuse  to  demand  fairly  pure  material  when  he  can 
do  so  at  little  or  no  extra  cost. 

Arsenic,  antimony,  or  any  other  elements  should  be  ab- 
sent, or  <  .005. 

FINISH   AND   GENERAL   CONDITIONS. 

As  there  can  be  no  such  thing  as  exact  work  done,  there 
must  be  some  tolerance  as  to  variation  in  size.  In  standard 
sections,  sheets,  and  plates  this  is  usually  covered  by  a  per- 
centage of  weight;  in  forgings  or  any  pieces  that  are  to  be 
machined  the  consumer  should  allow  enough  to  insure  a 
clean,  sound  surface.  But  it  would  be  unwise  to  lay  down 
any  rule  here,  because  conditions  vary;  a  rolled  round  bar 
may  finish  nicely  by  a  cut  of  from  -^  to  -^g  of  an  inch,  and 
so  also  a  neatly  dropped  forging ;  an  ordinary  hammered 
forging  might  require  a  cut  of  £  or  f  of  an  inch;  such  a 
forging  might  be  made  closer  to  size  at  a  cost  for  extra 
time  p.t  the  hammer  far  exceeding  the  saving  of  cost  in  the 


A    MANUAL    FOR   STEEL-USERS.  159 

lathe.  These  arc  cases  where  common-sense  and  good 
judgment  must  govern. 

Pipes  should  not  be  tolerated  if  they  can  be  discovered; 
because  a  pipe  appears  small  in  the  end  of  a  bar  it  is  no 
evidence  that  it  is  not  larger  farther  in. 

Seams  should  not  be  allowed  in  any  steel  that  is  to  be 
hardened  ;  they  should  be  a  mininum  iu  any  steel,  as  they 
are  of  no  possible  use  ;  small  seams  when  not  too  numer- 
ous may  do  no  harm  in  structural  or  machinery  steel,  and 
consumers  should  be  reasonable  in  regard  to  them,  or  else 
they  may  have  too  high  prices  put  upon  their  work,  or  too 
high  heat  used  in  efforts  to  close  the  last  few  harmless  seams. 

Burns,  rough,  ragged  holes  in  the  faces  or  on  the  corners, 
are  inexcusable  and  should  be  rejected  ;  the  steel  has  been 
abused,  or  it  is  red-short;  in  either  case  the  ragged  breaks 
are  good  starting-points  for  final  rupture. 

Laps  should  not  be  permitted  ;  they  are  evidences  of 
carelessness  ;  there  can  be  no  excuse  for  them. 

Fins  are  sometimes  unavoidable  in  a  difficult  shape;  for 
instance,  if  a  trapezoid  is  wanted,  it  may  be  rolled  in  this 
form  : 


or  in  this: 


160  STEEL: 

The  consumer  must  decide  which;  if  he  wants  sharp 
angles  he  must  accept  the  fin  and  cut  it  off,  or  have  it  cut 
off  by  the  manufacturer. 

Rivet-steel  should  be  tested  rigidly  for  red-shortness,  be- 
cause red-short  steel  may  crack  under  the  head  as  the  steel 
cools. 

Emphasis  is  laid  upon  this  because  engineers  will  insist 
upon  excessive  ductility  in  rivet-steel,  not  realizing  that 
they  may  be  requiring  the  manufacturer  to  overdose  his 
steel  with  oxygen  to  its  serious  injury. 

No  sharp  re-entrant  angles  should  be  allowed  under  any 
circumstances  where  there  is  a  possibility  of  vibrations  run- 
ning through  the  mass.  All  re-entrant  angles  should  be 
filleted  neatly. 

No  deep  tool-marks  should  be  allowed ;  a  fine  line  scored 
around  a  piece  by  a  lathe-tool,  or  a  sharp  line  cut  in  a  sur- 
face by  a  planing-tool  will  fix  a  line  of  fracture  as  neatly  as 
a  diamond-scratch  will  do  it  on  a  piece  of  glass. 

Indentations  by  hammers  or  sledges  should  be  avoided  ; 
they  may  not  be  as  dangerous  as  lathe-cuts,  but  they  can 
do  no  good,  and  therefore  they  are  of  no  use. 


A  MANUAL  FOR  STEEL-USEKS.  161 


XIV. 
HUMBUGS. 

STEEL  is  of  such  universal  use  and  interest  in  all  of  the 
arts  that  it  attracts  the  attention  of  would-be  inventors 
perhaps  more  than  any  other  one  material. 

Half-informed,  or  wholly  uninformed,  men  get  a  smat- 
tering of  knowledge  of  some  one  or  more  of  the  well-known 
properties  of  steel,  make  an  experiment  which  produces  a 
result  that  is  new  and  startling  to  them,  and  at  once 
imagine  that  they  have  made  a  discovery;  this  they  proceed 
to  patent  and  then  offer  it  to  the  world  with  a  great  flourish 
of  trumpets. 

Many  steel-workers,  even  men  of  skill,  who  know  some- 
thing of  the  difficulties  that  follow  irregular  work,  or  who 
are  not  quite  fully  informed  as  to  the  properties  of  steel, 
seize  upon  these  discoveries  in  the  hope  that  they  have 
found  a  royal  road  to  success  where  all  old  pitfalls  are 
removed  and  their  path  is  made  easy. 

Not  wishing  to  discourage  pioneers  in  legitimate  efforts 
to  improve,  it  is  the  object  of  this  chapter  to  warn  them 
against  being  too  ready  to  spend  their  money  because  of 
flaming  circulars  or  glib  tongues.  It  is  the  duty  and  the 
interest  of  a  steel  maker  to  examine  and  test  every  appar- 
ently new  suggestion,  for  the  reason  that  there  is  still  room 
for  improvement,  and  he  should  let  no  opportunity  for  a 
betterment  slip  past  him. 

As  a  rule  the  steel-maker  does  test  every  claim  that  is 
laid  before  him,  unless  it  be  a  repetition  of  some  old  plan 


162  STEKL: 

long  since  tried  and  found  worthless.  This  is  the  bane  of 
the  steel-maker's  life,  and  yet  he  must  keep  at  this  work 
so  that  he  may  know  for  himself  whether  anything  of  value 
has  been  discovered,  and  also  that  he  may  advise  his  client- 
age properly. 

Inventions  relating  to  the  manufacture  of  steel  have  no 
interest  for  steel-users  except  as  lively  manufacturers  mav 
adopt  the  mistaken  plan  of  flourishing  trumpets  to  attract 
trade,  not  always  giving  a  corresponding  benefit  to  the  con- 
sumer. 

Examples  of  this  sort  of  thing  may  be  illustrated  by  so- 
called  phosphorus  steel,  silicon  steel,  and  aluminum  steel; 
also  the  case  mentioned  before  of  parties  recommending 
seams  as  evidences  of  excellence  in  high  steel.  Such 
efforts  are  sometimes  costly  to  consumers  until  active  com- 
petitive manufacturers  expose  the  humbug. 

Among  the  most  absurd  of  such  claims  are  those  where  a 
nostrum  is  used  to  convert  ordinary  Bessemer  or  open- 
hearth  steel  into  the  finest  of  tool- steel,  equal  to  the  best 
crucible-steel;  for  example,  a  patent  to  convert  mild  Besse- 
mer steel  into  the  finest  tool-steel  by  merely  carbonizing  it 
by  the  old  cementation  process;  this  takes  no  account  of 
the  silicon,  manganese,  oxygen,  and  nitrogen  in  the  mild 
Bessemer,  makes  no  provision  for  their  removal,  and  in- 
volves a  costly  method  of  putting  carbon  into  poor  stock  in 
face  of  the  fact  that  a  Bessemer-steel  maker  can  put  the 
same  amount  of  carbon  there  at  practically  no  cost,  and  so 
produce  a  better  material. 

Among  the  humbugs  that  do  not  involve  the  manu- 
facturer, the  pet  one  is  a  nostrum  for  restoring  burnt  steel; 
these  have  been  evolved  by  the  dozen,  in  face  of  the  fact 
that  burned  steel  cannot  be  restored  except  by  smelting, 


A    MANUAL   FOR  STEEL-USERS.  163 

and  that  overheated  steel,  coarse-grained  steel,  can  be  re- 
stored by  merely  heating  it  to  the  right  temperature,  a 
process  which  has  been  explained  fully  in  Chapter  VI. 

Another  pet  is  some  greasy  compound  for  toughening 
high  steel  so  as  to  make  it  do  more  work.  This  is  done  by 
heating  the  steel  to  about  recalescence  and  plunging  it  into 
the  grease,  perhaps  once,  or  possibly  two  or  three  times; 
then  working  it  into  a  tool  and  proceeding  in  the  ordinary 
way.  This  will  make  a  good  tool;  it  is  the  partial  anneal- 
ing plan  explained  in  a  previous  chapter.  Now  take  a 
similar  piece  of  steel,  heat  it  the  same  way,  lay  it  down  in  a 
warm,  dry  place  alongside  the  forge-fire,  and  let  it  cool; 
then  heat  it  and  work  it  into  a  tool  and  it  will  beat  the 
greased  tool. 

When  all  of  these  operations  of  restoring,  partial  anneal- 
ing, annealing,  etc.,  depend  merely  upon  temperature  and 
rate  of  cooling,  why  spend  money  for  nostrums  that  add  no 
possible  benefit? 

Tlinre  is  room  for  improvement  in  steel,  great  room  for 
great  improvements;  they  will  come  in  time  as  science  and 
knowledge  advance,  and  great  benefits  to  the  consumers 
will  come  with  them. 

This  chapter  is  not  written  to  place  difficulties  in  the 
way  of  legitimate  improvement,  but  to  warn  unsuspecting 
people  against  quackery.  Some  of  the  humbugs  are  honest 
productions  of  well-meaning  ignorance,  and  some  that 
come  from  designing  manufacturers  are  not  entitled  to 
such  charitable  designation.  A  knowledge  of  the  simplest 
properties  of  steel  will  enable  a  thoughtful  man  to  judge 
as  to  whether  a  proposed  improvement  is  likely  to  be  of 
any  value  or  not,  and  the  warnings  given  are  intended  as  a 
protection  to  the  unsuspecting  and  credulous. 


164  si EEL: 


XV. 

CONCLUSIONS. 

AFTER  perusal  of  the  preceding  chapters  the  reader  may 
form  a  hasty  conclusion  that  if  steel  be  so  sensitive  as  it  is 
stated  to  be  its  use  may  be  difficult  and  precarious,  and 
that  it  must  be  handled  in  fear  and  trembling,  lest  the 
result  should  be  a  dangerous  structure,  and  the  builder 
must  be  in  doubt  as  to  its  safety. 

The  conveyance  of  any  such  impressions  is  not  intended 
at  all;  emphasis  has  been  laid  upon  practices  that  are 
hurtful  in  order  that  every  steel-user  may  know  what  to 
avoid,  solely  that  he  may  then  be  sure  that  he  has  the  best, 
the  most  reliable,  and  most  useful  material  that  is  known 
to  man. 

WHAT   TO   AVOID. 

He  should  avoid  uneven  heat,  excessive  heat,  or  too  lov 
heat.  The  range  between  orange  red  and  the  heat  that 
will  granulate  is  so  great  that  no  one  who  is  not  a  bungler 
or  indifferent  need  ever  get  outside  of  it. 

The  uniformity  of  temperature  that  is  insisted  upon  is 
so  easily  seen  that  any  person  who  is  not  color-blind  should 
have  no  trouble  in  securing  it  by  the  simplest  manipula- 
tions of  the  furnace. 

Practical  uniformity  of  the  work  put  on  a  piece  is  readily 
secured  by  any  mechanic  of  ordinary  skill. 


A   MANUAL  FOR  STEEL-USERS.  1(55 

Red-short,  cold-short,  or  honeycombed  steel  are  easily 
detected,  and,  under  reasonable  specifications,  the  steel- 
makers can  as  easily  avoid  them. 

Steel  a  little  higher  than  most  engineers  favor  in  their 
specifications  is  certainly  as  safe  as,  and  likely  to  be 
sounder  than,  extremely  ductile  steel. 

Wild  steel,  resulting  almost  certainly  in  micro-honey- 
combs, if  not  worse,  can  only  be  avoided  by  the  co-opera- 
tion of  the  manufacturer,  and  engineers  should  impress 
this  point  with  energy. 

Such  micro-unsoundness  as  is  shown  in  Mr.  Andrews's  re- 
port upon  a  broken  rail  and  propeller-shaft  can  be  reduced 
to  a  minimum  by  insisting  upon  reasonably  pure  steel. 

If  sulphur,  phosphorus,  silicon,  and  oxygen  are  kept  at  a 
reasonable  minimum,  sulphides,  phosphides,  silicides  or 
silicates,  and  oxides  must  be  at  a  corresponding  minimum. 

That  there  is  much  room  for  improvement  in  the  manu- 
facture of  steel  is  evident,  and  when  means  of  getting  rid 
of  oxygen,  nitrogen,  and  all  other  undesirable  elements 
have  been  found  the  steel  of  the  future  will  be  very  differ- 
ent in  kindliness  of  working  and  in  endurance  of  strains 
than  that  with  which  we  are  familiar. 

It  is  believed,  however,  that  no  matter  how  perfect  the 
manufacture  may  become,  nor  what  the  final  theories  of 
hardening,  etc.,  may  be,  the  properties  stated  in  these  pages 
will  remain  the  same  as  long  as  steel  continues  to  be  essen- 
tially a  union  of  iron  and  carbon. 

Some  other  alloy  or  compound  may  displace  carbon  steel, 
and  present  an  entirely  new  set  of  properties,  but  there  is 
nothing  of  the  kind  in  sight  now,  and  engineers  need  have 
no  fear  of  having  a  new  art  to  learn  very  soon. 

To  one  who  has  spent  an  ordinary  business  lifetime  in 


166  STEEL:  A  MANUAL  FOR  STEEL-USERS. 

making  steel,  studying  it,  and  working  with  it  it  becomes  a 
subject  of  absorbing  interest,  if  not  of  love  ;  and  steel  when 
handled  reasonably  is  so  true  that  "true  as  steel "  ceases 
to  be  a  metaphor,  it  is  then  a  fact  which  fills  him  with 
the  most  entire  confidence. 

Once  more,  steel  highly  charged  with  sulphur,  phos- 
phorus, arsenic,  oxygen,  and  nitrogen  is  certainly  highly 
charged  with  so  many  elements  of  disintegration  ;  it  takes 
more  serious  harm  from  ordinary  deviations  from  good 
practice,  such  little  irregularities  as  occur  inevitably  in 
daily  working,  than  steel  does  which  is  more  free  from  these 
elements. 

Reasonably  pure,  sound,  reliable  steel  can  be  had  at 
moderate  cost,  and  all  consumers  should  insist  upon  having 
it. 

Regular,  uniform,  reliable  working  can  be  had  where  it 
is  required,  and  there  should  be  no  excuse  for  irregular 
grain,  overheated  work,  uneven  work,  or  any  other  bung- 
ling. Where  skill  is  required  and  reasonable  discipline  is 
enforced,  good  work  will  not  cost  any  more  than  bad  work. 

Many  people  still  hold  to  the  idea  that  there  are  many 
mysteries  connected  with  steel,  and  that  many  unaccount- 
able breaks  occur  which  make  it  an  unreliable  material. 
It  is  hoped  that  what  has  been  set  down  in  these  pages 
will  go  far  to  dissipate  these  supposed  mysteries,  and  to 
give  confidence  to  steel-users. 

Many  breaks  are  unaccounted  for,  but  it  is  not  within 
the  author's  experience  that  any  fracture  ever  occurred 
that  could  not  have  been  explained  if  it  had  been  exam- 
ined thoroughly  in  the  light  of  what  we  know  now.  There 
is  much  to  be  learned,  but  there  are  no  mysteries. 


GLOSSARY. 


THERE  are  many  shop  terms  used  in  this  book  which  may  not  be 
familiar  to  all  steel-users. 

They  are  in  common  use  in  steel-manufactories,  and  definitions  of 
them  will  enable  a  steel-user  to  understand  more  clearly  the  common 
talk  he  will  hear  in  the  shops. 

Blow-holes. — Blow-holes  are  the  small  cavities,  usually  spherical, 
which  are  formed  in  ingots  as  the  steel  congeals  by  bubbles  of  gas 
which  cannot  escape  through  the  already  frozen  surface. 

Earned.  —  Burned  steel  is  steel  that  is  reduced  to  oxide  in  part  by 
excessive  heating. 

Check. — A  check  is  a  small  rupture  caused  by  water;  it  may  run  in 
any  direction  ;  it  is  usually  not  visible  until  steel  is  ruptured. 

Chemical  Numeration.— Chemical  quantities  are  almost  universally 
expressed  in  hundredths  of  one  per  cent,  as  explained  in  the  body  of 
the  work.  It  is  a  very  convenient  numeration;  any  steel-worker, 
melter,  hammerman,  etc.,  will  talk  of  20,  or  50.  or  130  carbon;  or  8 
phosphorus;  or  10,  15.  or  25  silicon,  etc.;  and  will  talk  intelligently, 
although  he  may  not  know  the  exact  mathematical  value  of  these 
points. 

Dead-melting;  synonym,  killing.  —  Dead-melting — killing — means 
melting  steel  in  the  crucible  or  open  hearth  until  it  ceases  to  boil  or 
evolve  gases;  it  is  then  dead,  it  lies  quiet  in  the  furnace,  and  killed 
properly  it  will  set  in  the  moulds  without  rising  or  boiling. 

Dry.— Steel  is  called  dry  when  its  fracture  is  sandy-looking,  with- 
out lustre  or  sheen,  and  without  a  proper  blue  cast.  There  is  more 
of  a  shade  of  yellowish  sandstone.  It  is  an  evidence  of  impurity  and 
weakness. 

Fiery. —Fiery  steel  has  a  brilliant  lustre;  it  is  an  evidence  of  high 
heat. 

167 


168 

If  the  grain  be  fairly  fine  and  of  bluish  cast,  it  is  not  necessarily 
bad  in  mild  steel;  in  high  steel  or  in  tool- steel  it  should  not  be 
tolerated. 

If  the  grain  be  large  and  of  brassy  cast,  it  is  sure  evidence  of  bad 
condition ;  the  grain  should  be  restored  before  the  steel  is  used. 

In  hardened  steel  it  is  always  bad,  except  in  dies  to  be  used  under 
the  impact  of  drop-hammers;  in  this  case  steel  must  be  so  hard  as  to 
be  slightly  fiery. 

Grade. — (irade  applies  to  quality,  as  crucible,  Bessemer,  or  open- 
hearth  grade.  Or  in  the  crucible,  common,  spring,  machinery,  tool, 
special  tool,  etc. ,  etc.  It  does  not  indicate  temper  or  relative  hardness. 

Honeycombed. — Unsound  from  many  blow-holes.  Usually  applied 
to  ingots.  It  is  a  bad  condition. 

Lap. — A  lap  is  caused  by  careless  hammering,  or  by  badly  propor- 
tioned grooves  in  rolls,  or  by  careless  rolling.  A  portion  of  the  steel 
is  folded  over  on  itself,  the  walls  are  oxidized  and  cannot  unite.  A  lap 
generally  runs  clear  along  a  bar,  practically  parallel  with  its  axis;  it 
may  be  seen  by  a  novice.  Lapped  steel  should  be  rejected  always. 

Overblown. — Steel  that  has  been  blown  in  a  Bessemer  converter 
after  the  carbon  is  all  burned;  then  there  is  nothing  but  steel  to  burn, 
and  the  result  is  bad. 

Overheated. — Steel  that  has  been  healed  too  hot,  and  not  quite 
burned;  its  fiery  fracture  exposes  it.  The  grain  of  overheated  steel 
may  be  restored,  but  restored  steel  is  never  as  reliable  as  steel  that 
has  not  been  overheated.  Overheating  is  a  disintegrating  operation. 

Overmelted. — Steel  that  has  been  kept  too  long  in  fusion.  The 
finest  material  may  be  ruined  in  a  crucible  by  being  kept  in  the 
furnace  any  considerable  time  after  it  has  been  killed.  Open-hearth 
steel  may  be  injured  seriously  in  the  same  way.  Prompt  teeming  after 
killing  should  be  the  rule. 

Pipe. — A  pipe  is  the  cavity  formed  in  an  ingot  when  it  cools;  the 
avails  chill  first  and  nearly  to  the  full  si/e  of  the  mould,  then  the 
shrinking  mass  separates  in  the  middle,  forming  a  pipe.  A  pipe 
should  be  at  the  top  of  the  ingot;  it  may  occur  anywhere  by  bad 
teeming. 

Point.—  One  hundredth  of  one  per  cent  of  any  clement.  You  have 
say  10  points  of  carbon,  or  10  carbon;  you  want  it  raised  a  few  points 
to  15  or  18  carbon, 


GLOSSARY.  169 

Eecalescence.—  When  a  piece  of  steel  is  heated  above  medium 
orange  color  and  cools  slowly,  at  about  medium  orange— 1100°  to 
1200°  F. — the  change  of  color  ceases,  then  the  color  rises  sometimes 
to  bright  orange,  and  afterwards  the  cooling  goes  on;  this  phenome- 
non is  called  recalescence.  This  is  not  yet  a  common  shop  term. 

Restoring.—  When  a  piece  of  overheated  steel  is  re-heated  to  re- 
calescence, kept  there  a  few  minutes,  and  then  cooled  slowly,  its  grain 
becomes  fine  and  its  fiery  lustre  disappears;  this  is  called  restoring. 
No  nostrums  are  necessary. 

Sappy.— Well- worked,  good  steel  has  a  bluish  cast,  a  fine  grain, 
and  a  silky  sheen.  It  is  sappy;  it  is  as  good  as  it  can  be  made. 

Seam.— A  seam  is  a  longer  or  shorter  defect,  caused  by  a  blow-hole 
which  working  has  brought  out  to  the  surface  and  not  eliminated. 
It  usually,  or  always,  runs  in  the  direction  of  working.  Seams  are 
distinguished  from  laps  by  not  being  continuous;  they  are  usually 
only  an  inch  or  two  in  length. 

Short  (Cold,  Bed,  Hot).— Cold-short  steel  is  weak  and  brittle  when 
cold. 

Red-short  steel  is  brittle  at  dark  orange  or  medium  orange  heat  or 
at  the  common  cherry-red  heat.  It  may  forge  well  at  a  lemon  heat, 
and  be  reasonably  tough  when  cold. 

Hot-short  steel  is  brittle  and  friable  above  a  medium  orange  color; 
it  may  forge  well  from  medium  orange  down  to  black  heat. 

Star. — A  brilliant  spot  in  mid-section  showing  that  the  pipe  is  not 
all  cut  away.  It  should  be  removed  from  tool-steel  especially,  as  it 
may  have  considerable  depth.  It  is  of  no  use  in  any  steel. 

Temper. — Used  by  the  steel-maker  it  means  the  quantity  of  carbon 
present.  It  is  low  temper,  medium,  or  high;  or  number  so  and  so  by 
his  shop  numbers. 

Used  by  the  steel-user  or  the  temperer  it  means  the  color  to  which 
.mrdened  steel  is  drawn:  straw,  brown,  pigeon- wing,  blue,  etc.,  etc. 

Or.  it  is  the  steel-makers  measure  of  initial  hardness;  and  it  is  the 
steel  user's  measure  of  final  hardness. 

Water-crack.— A  crack  caused  in  hardening;  it  may  run  in  any 
direction  governed  by  lines  of  stress  in  the  mass.  It  is  distinguished 
from  a  check  by  being  larger,  and  usually  plainly  visible. 

"Wild  Steel.— Steel  in  fusion  that  boils  violently,  and  acts  in  the 
moulds  like  lively  soda-water  or  beer  does  when  poured  into  a  glass. 


SHORT-TITLE     CATALOGUE 

OF  THE 

PUBLICATIONS 

OF 

JOHN  WILEY   &   SONS, 

NEW    YORK. 

LONDOX:    CHAPMAX  &  HALL,  LIMITED. 
ARRANGED  UNDER  SUBJECTS. 


ive  circulars  sent  on  application. 
Books  marked  xvith  an  asterisk  are  sold  at  net  prices  onlv 
All  books  ar«  bound  in  cloth  unl.-ss  otherwise  stated 


AGRICULTURE. 

Armsby's  Manual    of  Cattle-fending 12mo,  $1  76 

Principles  of  Animal  Nutrition . .  .gvo,  4  00 

Budd  and  Hansen's  American  Horticultural  Manual: 

.—Propagation.  Culture,  and    Improvement. ..  ,12mo,  160 
Part  II.— Systematic  Pomology.     (In  preparation.) 

ftowning's  Fruita  and  Fruit-tree*  of  America 8vo,  5  00 

Elliott's  Engineering  for  Land  Drainage 12mo  1  50 

Urotenfelt's  Principles  of  Modern  Dairy  Practice.   (Woll.)..12mo,'  2  00 

Kemp's  Landscape  Gardening *. 12mo,  2  60 

Waynard's  Landscape  Gardening  as  Applied  to  Home  Decoration. 

12mo,  1  60 

Banderson's  Insects  Injurious  to  Staple  Crops 12mo,  1  60 

Insects  Injurious  to  Garden  Crops.     (In  preparation.) 
Insects  Injuring  Fruits.     (In  preparation.) 

Btockbridge's  Rocks  and  Soils 8vo,  2  60 

Well's  Handbook  for  Farmers  and  Dairymen 16mo,  1  60 

ARCHITECTURE. 

Baldwin's  Steam  Heating  for  Buildings 12mo,  2  50 

Berg's  Buildings  and  Structures  of  American  Railroads 4to,  5  00 

Birkmire's  Planning  and  Construction  of  American  Tb.eatres.8vo,  3  00 

Architectural  Iron  and  Steel 8vo,  3  60 

"          Compound  Riveted  Girders  as  Applied  in  Buildings. 

8vo,  2  00 
"          Planning  and  Construction  of  High  Office  Buildings. 

8vo,  3  60 

"          Skeleton  Construction  in  Buildings 8vo,  3  00 

Briggs's   Modern   American   School   Buildings ...8vo,  400 

Carpenter's  Heating  and  Ventilating  of  Buildings 8vo,  4  00 

Freitag's  Architectural  Engineering.  2d  Edition,  Rewritten. 8vo,  350 

Fireproofing  of  Steel  Buildings 8vo,  2  60 

French  and  Ives's  Stereotomy 8vo,  2  50 

Gerhard's  Guide  to  Sanitary  House-inspection 16mo,  1  00 

"          Theatre  Fires  and  Panics 12mo,  1  60 

Hatfleld's  American  House  Carpenter 8vo,  5  00 

Holly's  Carpenters'  and  Joiners'  Handbook 18mo,  76 

Kidder's  Architect's  and  Builder's  Pocket-book. .  16mo,  morocco,  4  00 
1 


Merrill's  Stones  for  Building  and  Decoration 8vo,  5  00 

Monckton's  Stair-building 4to,  4  00 

Patton's  Practical  Treatise  on  Foundations 8vo,  5  00 

Siebert  and  Biggin's  Modern  Stone-cutting  and  Masonry.  .8vo,  1  50 
Snow's  Principal  Spt-oi«  s  of  Wood:  Their  Characteristic  Proper- 
ties.    (In  preparation.) 

Wait's  Engineering  and  Architectural  Jurisprudence 8vo,  6  00 

Sheep,  6  50 

"      Law  of  Operations  Preliminary  to  Construction  in  En- 
gineering and  Architecture 8vo,  5  00 

Sheep,  5  50 

"      Law  of  Contracts 8vo,  3  00 

Woodbury's  Fire  Protection  of  Mills 8vo,  2  50 

Worcester  and  Atkinson's  Small  Hospitals,  Establishment  and 
Maintenance,  and  Suggestions  for  Hospital  Architecture, 

with  Plans  for  a  Small  Hospital 12mo,  1  25 

The  World's  Columbian  Exposition  of  1893 Large  4to,  1  00 

ARMY  AND  NAVY. 

Bernadou's  Smokeless  Powder,  Nitro-cellulose,  and  the  Theory 

of    the    Cellulose    Molecule 12mo,  250 

*  Bruff's  Text-book  Ordnance  and  Gunnery 8vo,  6  00 

Chase's  Screw   Propellers  and  Marine  Propulsion 8vo,  3  00 

Craig's   Azimuth 4to,  3  50 

Crehore  and  Squire's   Polarizing  Photo-chronograph 8vo,  3  00 

Cronkhite's  Gunnery  for   Non-commissioned  Officers..24mo,mor.,  2  00 

*  Davis's  Elements  of  Law 8vo,  2  50 

*  "      Treatise  on  the  Military  Law  of  United  States.. 8vo,  7  00 

Sheep,  7  50 

De  Brack's  Cavalry  Outpost  Duties.     (Carr.) 24mo,  morocco,  2  00 

Dietz's  Soldier's  First  Aid  Handbook 16mo,  morocco,  1  25 

*  Dredge's  Modern  French  Artillery 4to,  half  morocco,  15  00 

Durand's  Resistance  and  Populsion  of  Ships 8vo,  5  00 

*  Dyer's  Handbook  of  Light  Artillery 12mo,  3  00 

Eissler's    Modern    High    Explosives 8vo,  400 

*  Fiebeger's  Text- book  on  Field  Fortification Small  8vo,  2  00 

Hamilton's  The  Gunner's  Catechism 18mo,  1  00 

*  Hoff's  Elementary  Naval  Tactics 8vo,  1  50 

Ingalls's  Handbook  of  Problems  in  Direct  Fire 8vo,  4  00 

*  "        Ballistic  Tables 8vo,  1  50 

Lyons's  Treatise  on  Electromagnetic  Phenomena 8vo,  6  00 

*  Mahan's  Permanent  Fortifications.     (Mercur.)..8vo,  half  mor.,  7  50 
Manual    for    Courts-martial 16mo,    morocco,  1  50 

*  Mercur's  Attack  of  Fortified  Places 12mo,  2  00 

"         Elements  of  the  Art  of  War 8vo,  4  00 

Metcalfs  Cost  of  Manufactures — And  the  Administration  of 

Workshops,    Public    and    Private 8vo,  500 

Ordnance  and  Gunnery 12mo,  5  00 

Murray's  Infantry  Drill  Regulations 18mo,  paper,  10 

*  Phelps's    Practical   Marine    Surveying 8vo,  2  60 

Powell's  Army  Officer's  Examiner 12mo,  4  00 

Sbarpe's  Art  of  Subsisting  Armies  in  War 18mo,  morocco,  1  50 

Walke's  Lectures  on  Explosives 8vo,  4  00 

*  Wheeler's  Siege  Operations  and  Military  Mining 8vo,  2  00 

Winthrop'a  Abridgment  of  Military  Law 12mo,  2  50 

Woodhull's  Note*  on  Military  Hygiene 16mo,  1  50 

Young's  Simple  Elements  of  Navigation 16mo,  morocco,  1  00 

Second  Edition,  Enlarged  nnd  Revised 18mo,  mor.,  2  00 

1 


ASSAYING. 

Fletcher's  Practical  Instructions  in  Quantitative  Assaying  with 

the  Blowpipe 12mo,  morocco,  1  60 

Funnan's  Manual  of  Practical  Assaying 8vo,  3  00 

Miller's  Manual  of  Assaying 12mo,  1  00 

O'Driscoll's  Notes  on  the  Treatment  of  Gold  Ores 8vo,  2  00 

Ricketts  and  Miller's  Notes  on  Assaying 8vo,  3  00 

Wilson's  Cyanide  Processes 12mo,  1  60 

Chlorination  Process 12mo,  1  60 

ASTRONOMY. 

Comstock's  Field  Astronomy  for  Engineers 8vo,  2  50 

Craig's  Azimuth 4to,  3  50 

Doolittle's  Treatise  on  Practical  Astronomy 8vo,  4  00 

Gore's  Elements  of  Geodesy 8vo,  2  60 

Hayford's  Text-book  of  Geodetic  Astronomy 8vo,  3  00 

Merriman's  Element*  of  Precise  Surveying  and  Geodesy 8vo,  2  60 

*  Michie  and  Harlow's  Practical  Astronomy 8vo,  3  00 

•  White's  Element*  of  Theoretical  and  Descriptive  Astronomy. 

12rao,  2  00 

BOTANY. 

Baldwin's  Orchids  of  New  England Small  8vo,  1  50 

Davenport's  Statistical  Methods,  with  Special  Reference  to  Bio- 
logical   Variation 16mo,   morocco,  1  25 

Thome1  and  Bennett's  Structural  and  Physiological  Botany. 

16mo,  2  26 

Westcrmaier's  Compendium  of  General  Botany. (Schneider.)  8vo,  2  00 

CHEMISTRY. 

Adriance's  Laboratory  Calculations  and  Specific  Gravity  Tables. 

12mo,  1  26 

Allen's  Tables  for  Iron  Analysis 8vo.  3  00 

Arnold's  Compendium  of  Chemistry.  (Mandel.)    (In  preparation.) 

Austen's  Notes  for  Chemical  Students 12mo,  1  60 

Bernadou's  Smokeless  Powder. — Nitro-cellulose,  and  Theory  of 

the  Cellulose  Molecule 12mo,  2  50 

Bolton's  Quantitative  Analysis 8vo,  1  50 

Brush  and  Penfield's  Manual  of  Determinative  Mineralogy ...8vo,  4  00 
Classen's  Quantitative  Chemical  Analysis  by  Electrolysis.    (Her- 

rick— Roltwood.)   8vo,  3  00 

Cohn's  Indicators  and  Test-papers 12mo,  2  00 

Craft's  Short  Course  in  Qualitative  Chemical  Analysis.  (Schaef- 

fer.)    12mo,  200 

Drechsel's  Chemical   Reactions.     (Merrill.) 12mo,  125 

Eissler's  Modern  High  Explosives 8vo,  4  00 

Effront's  Enzymes  and  their  Applications.     (Prescott.) 8vo,  3  00 

Erdmann's  Introduction  to  Chemical  Preparations.     (Dunlap.) 

12mo,  1  2S 
Fletcher's  Practical  Instructions  in  Quantitative  Assaying  with 

the  Blowpipe 12mo,  morocco,  1  60 

Fowler's  Sewage  Works  Analyses 12mo,  2  00 

Fresenius's  Manual  of  Qualitative  Chemical  Analysis.  (Wells.)  8vo,  5  00 
"        Manual  of  Qualitative  Chemical  Analysis.     Part  I. 

Descriptive.     (Wells.) 8vo.  300 

"          System   of  Instruction   in   Quantitative  Chemical 

Analysis.      (Allen.) 8vo,  800 

3 


Fuertes's  Water  and  Puolic  Health 12mo,  1  50 

Furman's  Manual  of  Practical  Assaying 8vo,  3  00 

Gill's  Gas  and  Fuel  Analysis  for  Engineers 12tno,  1  25 

Grotenfelt's  Principles  of  Modern  Dairy  Practice.   (Woll.)..12rao,  200 
Hamniarsten's  Text-book  of  Physiological  Chemistry.  (Mandel.) 

8vo,  4  00 

Helm's  Principles  of  Mathematical  Chemistry.  (Morgan.)   12mo,  1  60 

Hinds's  Inorganic  Chemistry 8vo,  3  00 

*  j  "        Laboratory  Manual  for  Students 12mo,  75 

Holleman's  Text-book  of  Inorganic  Chemistry.   (Cooper.) ..  .8vo,  250 

"      "  Organic  "     (Walker  and  Mott.) 

(In  preparation.) 

Hopkins's  Oil-chemists'  Handbook 8vo,  3  00 

Keep's  Cast  Iron 8vo,  2  50 

Ladd's  Manual  of  Quantitative  Chemical  Analysis 12mo,  1  00 

Landauer's  Spectrum  Analysis.     (Tingle.) 8vo,  3  00 

Lassar-Cohn's  Practical  Urinary  Analysis.   (Lorenz.)    (In  preparation.) 
Leach's  The  Inspection  and  Analysis  of  Food  with  Special  Refer- 
ence to  State  Control.     (In  preparation.) 
Lob's  Electrolysis  and  Electrosynthesis  of  Organic  Compounds. 

(Lorenz.)    12mo,  1  00 

Mandel's   Handbook   for  Bio-chemical   Laboratory 12mo,  150 

Mason's  Water-supply.     (Considered  Principally  from  a  Sani- 
tary Standpoint.)  3d  Edition,  Rewritten 8vo,  4  00 

Examination    of    water.       (Chemical    and    Bacterio- 
logical.)    12mo,  1  26 

Meyer's    Determination    of    Radicles    in    Carbon    Compounds. 

(Tingle.)  12mo,  1  00 

Miller's  Manual  of  Assaying 12mo,  1  00 

Mixter's  Elementary  Text-book  of  Chemistry 12mo,  1  60 

Morgan's  Outline  of  Theory  of  Solution  and  its  Results.  .12mo,  1  00 

Elements  of  Physical  Chemistry. 12mo,  2  00 

Nichols's  Water-supply.     (Considered  mainly  from  a  Chemical 

and  Sanitary  Standpoint,  1883.) 8vo,  2  50 

O'Brine's  Laboratory  Guide  in  Chemical  Analysis 8vo,  2  00 

O'DriscolPs  Notes  on  the  Treatment  of  Gold  Ores 8vo,  2  00 

Ost  and  Kolbeck's  Text-book  of  Chemical  Technology.      (Lo- 
renz— Bozart.)     (In  preparation.) 

*  Penfield's  Notes  on  Determinative  Mineralogy  and  Record  of 

Mineral  Tests 8vo,  paper,  0  60 

Pinner's  Introduction  to  Organic  Chemistry.     (Austen.)    ,12mo,  1  60 

Poole's  Calorific  Power  of  Fuels 8vo,  3  00 

*  Reisig's  Guide  to  Piece-dyeing 8vo,  25  00 

Richards  and  Woodman's  Air,  Water,  and  Food  from  a  Sanitary 

Standpoint  8vo,  2  00 

Richards's  Cost  of  Living  as  Modified  by  Sanitary  Science    12mo,  100 

Cost  of  Food,  a  Study  in  Dietaries 12mo,  1  00 

*  Richards  and  Williams's  The  Dietary  Computer. . , 8vo,  1  60 

Ricketts  and  Russell's  Skeleton  Notes  upon  Inorganic  Chem- 
istry.     (Parti.— Non-metallic  Elements.)..  8vo,  morocco,  76 

Ricketts  and  Miller's  Notes  on  Assaying. 8vo,  3  09 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage.  .8vo,  3  50 

Ruddiman's  Incompatibilities  in  Prescriptions 8vo,  2  00 

Bchimpf's  Text-book  of  Volumetric  Analysis 12mo,  2  60 

Spencer's  Handbook  for  Chemists  of  Beet-sugar  Houses.  16mo, 

mor.,  3  00 

Handbook  for  Sugar  Manufacturers  and  their  Chem- 
ist9   16mo,  morocco,  2  00 

Btockbridge's  Rocks  and  Soils 8vo,  2  60 

4 


•  Tillman's  Elementary  Lessons  in  Heat 8vo  1  50 

Descriptive  General  Chemistry....  8vo'  3  Oi 

Turneaure  and  Russell's  Public  Water-supplies..  "  Wo'  5  00 

Van  Deventer'a  Physical  Chemistry  for  Beginners.  (Boltwood.)' 

Walke's  Lectures  on  Explosives ,  .  .^g™?  J  JJJJ 

Wells's  Laboratory  Guide  in  Qualitative  Chemical  Analysis..8vo'  1  50 
Short  Course  in  Inorganic  Qualitative  Chemical  Analy- 
sis for  Engineering  Students 12mo  1  50 

Whipple's  Microscopy  of  Drinking-water 8vo  3  50 

Wiechmann's  Sugar  Analysis Small  8vo,  2  50 

Wilson's  Cyanide  Processes 12mo  1  50 

Chlorination    Process 12mo'  1  50 

Wulling's  Elementary  Course  in  Inorganic  Pharmaceutical  and 

Medical  Chemistry 12mO)  2  00 

CIVIL  ENGINEERING. 

BRIDGES     AND     ROOFS.       HYDRAULICS.       MATERIALS     OF 
ENGINEERING.     RAILWAY  ENGINEERING. 

Baker's  Engineers'  Surveying  Instruments 12mo,    3  00 

Bixby's  Graphical  Computing  Table.  ..Paper,  19Jx24$  inches.        25 
^Burr's  Ancient  and  Modern  Engineering  and  the  Isthmian 

Canal (Postage,  27  cents  additional)     8vo,  net,    3  50 

Comstock's  Field  Astronomy  for  Engineers 8vo,    2  50 

Da  vis's  Elevation  and  Stadia  Tables 8vo,     1  00 

Elliott's  Engineering  for  Land  Drainage 12mo,    1  50 

Folwell's  Sewerage.     (Designing  and  Maintenance.) 8vo,    3  00 

Freitag's  Architectural  Engineering.    2d  Ed.,  Rewritten. .  .8vo,    3  50 

French  and  Ives's  Stereotomy 8vo,     2  50 

Goodhue's  Municipal  Improvements 12mo,     1  75 

Goodrich's  Economic  Disposal  of  Towns'  Refuse 8vo,    3  50 

Gore's  Elements  of  Geodesy 8vo,    2  50 

Hayford's  Text-book  of  Geodetic  Astronomy 8vo,    3  00 

Howe's  Retaining-walls  for  Earth 12mo,     1  25 

Johnson's  Theory  and  Practice  of  Surveying Small  8vo,    4  00 

Stadia  and  Earth-work  Tables 8vo,     1  25 

Kiersted's  Sewage  Disposal 12mo,     1  25 

Laplace's  Philosophical  Essav  on  Probabilities.    (Truscott  and 

Emory.) 12mo,     2  00 

Mahan's  Treatise  on  Civil  Engineering.    (1873.)    (Wood.).  .8vo,    5  00 

*  Mahan's  Descriptive  Geometry 8vo,     1  50 

Merriman's  Elements  of  Precise  Surveying  and  Geodesy. . .  .8vo,    2  60 
Merriman  and  Brooks's  Handbook  for  Surveyors. ..  .16mo,  mor.,    2  00 

Merriman's  Elements  of  Sanitary  Engineering 8vo,    2  00 

Nupent's  Plane  Surveying 8vo,    3  50 

Ogden's  Sewer  Design 12mo,    2  00 

Patton's  Treatise  on  Civil  Engineering 8vo,  half  leather,    7  50 

Reed's  Topographical  Drawing  and  Sketching 4to,    5  00 

Rideal's  Sewage  and  the  Bacterial  Purification  of  Sewage..  .8vo,    3  50 

Siebert  and  Biggin's  Modern  Stone-cutting  and  Masonry 8vo,     1  50 

Smith's  Manual  of  Topographical  Drawing.    (McMillan.) .  .8vo,    2  50 
•Trautwine's  Civil  Engineer's  Pocket-book. ..  .16mo,  morocco,    5  00 

Wait's  Engineering  and  Architectural  Jurisprudence 8vo,    6  00 

Sheep,    6  50 

"      Law  of  Operations  Preliminary  to  Construction  in  En- 
gineering and  Architecture 8vo,    5  00 

Sheep,    5  50 

Wait's   Law   of   Contracts 8vo,    3  00 

Warren's  Stereotomy — Problems  in  Stone-cutting 8vo,        2  50 

5 


Webb's  Problems  in  the  Use  and  Adjustment  of  Engineering 

Instruments   16mo,  morocco,  1  25 

*  Wheeler's  Elementary  Course  of  Civil  Engineering 8vo,  4  00 

Wilson's  Topographic  Surveying 8vo,  3  50 

BKIDGES  AND  ROOFS. 

Boiler's  Practical  Treatise  on  the  Construction  of  Iron  Highway 

Bridges 8vo,  2  00 

"  Boiler's  Thames  River  Bridge 4to,  paper,  5  00 

Burr's  Course  on   the  Stresses  in  Bridges  and   Roof   Trusses, 

Arched  Ribs,  and  Suspension  Bridges 8vo,  3  50 

Du  Bois's  Mechanics  of  Engineering.    Vol.  II Small  4to,  10  00 

Foster's  Treatise  on  Wooden  Trestle  Bridges 4to,  5  00 

Fowler's  Coffer-dam  Process  for  Piers 8vo,  2  50 

Greene's  Roof  Trusses 8vo,  1  25 

"           Bridge   Trusses 8vo,  2  50 

"          Arches  in  Wood,  Iron,  and  Stone 8vo,  2  50 

Howe's  Treatise  on  Arches 8vo,  4  00 

"       Design  of  Simple  Roof-trusses  in  Wood  and  Steel .  Svo,  2  00 
Johnson,  Bryan  and  Tumeaure's  Theory  and  Practice  in  the 

Designing  of  Modern  Framed  Structures Small  4to,  10  00 

Merriman  and  Jacoby*s  Text-book  on  Roofs  and  Bridges: 

Part  I.— Stresses  in  Simple  Trusses Svo,  2  50 

Part  II.— Graphic  Statics Svo,  2  50 

Part  III.— Bridge  Design.     Fourth  Ed.,  Rewritten 8vo,  2  50 

Part  IV. — Higher  Structures Svo,  2  60 

Morison's  Memphis  Bridge 4to,  10  00 

Waddell's  De  Pontibus,  a  Pocket  Book  for  Bridge  Engineers. 

16mo,  mor.,  3  00 

Specifications  for  Steel  Bridges 12mo,  1  26 

Wood's  Treatise  on  the  Theory  of  the  Construction  of  Bridges 

and  Roofs  Svo,  2  00 

Wright's  Designing  of  Draw-spans: 

Part   I.— Plate-girder  Draws Svo,  2  50 

Part  II.— Riveted-truss  and  Pin-connected  Long-span  Draws. 

Svo,  2  60 

Two  parts  in  one  volume Svo,  3  60 

HYDRAULICS. 

Bazin's  Experiments  upon  the  Contraction  of  the  Liquid  Vein 

Issuing  from  an  Orifice.     (Trautwine.) Svo,  2  00 

Bovey's  Treatise  on  Hydraulics Svo,  6  00 

Church's  Mechanics  of  Engineering Svo,  6  00 

Diagrams  of  Mean  Velocity  of  Water  in  Open  Channels 

paper,  1  50 

Coffin's  Graphical  Solution  of  Hydraulic  Problems.  .16mo,  mor.,  2  60 

Flather's  Dynamometers,  and  the  Measurement  of  Power.  12mo,  3  00 

Folwell's  Water-supply  Engineering Svo,  4  00 

FrizelFs    Water-power Svo,  5  00 

Fuertes's   Water   and    Public  Health 12mo,  150 

Water-filtration    Works 12mo,  2  60 

Ganguillet   and   Kutter's   General    Formula   for   the   Uniform 
Flow   of  Water  in  Rivers  and   Other   Channels.     (Her- 

ing  and  Trautwine.) Svo,  4  00 

Haren's  Filtration  of  Public  Water-supply Svo,  3  00 

Hazlehurst's  Towers  and  Tanks  for  Water-works Svo,  2  60 

Herschel's  115  Experiments  on  the  Carrying  Capacity  of  Large, 

Riveted,  Metal  Conduits Svo,  Z  00 

6 


Mason's  Water-supply.     (Considered  Principally  from  a  Sani- 
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Weisbach's  Hydraulics  and  Hydraulic  Motors.    (Du  Bol».) .  .8vo,  5  Of 

Wilson's  Manual  of  Irrigation  Engineering Small  8vo,  4  00 

Wolff's  Windmill  as  a  Prime  Mover 8vo,  3  00 

Wood's  Turbines 8vo,  2  60 

Elements  of  Analytical  Mechanics 8vo,  3  00 

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Burr's  Elasticity  and  Resistance  of  the  Materials  of  Engineer- 
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Keep's  Cast  Iron '. 8vo,  t  M 

Lanza's  Applied  Mechanics 8vo,  7  •• 

Martens's  Handbook  on  Testing  Materials.  (Henning.).2  v.,  8vo,  7  50 

Merrill's  Stones  for  Building  and  Decoration 8vo,  5  00 

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8 


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14 


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Mason's   Water-supply.     (Considered   Principally  from   a  San- 
itary Standpoint.     3d  Edition,  Rewritten 8vo,  4  00 

"        Examination    of    Water.      (Chemical    and    Bacterio- 
logical.)      12mo,  1  26 

Merriman's  Elements  of  Sanitary  Engineering 8vo,  2  00 

Nichols's  Water-supply.     (Considered  Mainly  from  a  Chemical 

and  Sanitary  Standpoint.)     ( 1883.)  8vo,  2  60 

Ogden's  Sewer  Design 12mo,  2  00 

*  Price's  Handbook  on  Sanitation 12mo,  1  60 

Richards's  Cost  of  Food.    A  Study  in  Dietaries 12mo,  1  Of 

Richards  and  Woodman's  Air,  Water,  and  Food  from  a  Sani- 
tary   Standpoint 8vo,  2  00 

Richards's  Cost  of  Living  as  Modified  by  Sanitary  Science.  12mo,  1  00 

•  Richards  and  Williams's  The  Dietary  Computer 8vo,  1  60 

Rideal's  Sewage  and  Bacterial  Purification  of  Sewage 8vo,  8  60 

Turneaure  and  Russell's  Public  Water-supplies 8vo,  5  00 

Whipple's  Microscopy  of  Drinking-water 8vo,  3  60 

WoodhulPs  Notes  on  Military  Hygiene 16mo,  1  60 


MISCELLANEOUS. 

Barker's  Deep-sea  Soundings 8vo,  2  00 

Emmous's  Geological  Guide-book  of  the  Rocky  Mountain  Ex- 
cursion   of    the    International    Congress    of    Geologists. 

Large  8vo,  1  60 

Fen-el's  Popular  Treatise  on  the  Winds .8vo,  4  00 

Haines's  American  Railway  Management 12mo,  2  60 

Mott's  Composition,  Digestibility,  and  Nutritive  Value  of  Food. 

Mounted  chart,  1  26 

"      Fallacy  of  the  Present  Theory  of  Sound 16mo,  1  00 

Ricketts's  History  of  Rensselaer  Polytechnic  Institute,   1824- 

1894 Small    8vo,  3  00 

Rotherham's  Emphasised  New  Testament Large  8vo,  2  Of 

Steel's  Treatise  on  the  Diseases  of  the  Dog 8vo,  3  60 

Totten's  Important  Question  in  Metrology 8vo,  2  6f 

The  World's  Columbian  Exposition  of  1893 4to,  1  00 

Worcester  and  Atkinson.     Small  Hospitals,  Establishment  and 
Maintenance,  and  Suggestions  for  Hospital  Architecture, 

with  Plans  for  a  Small  Hospital 12mo,  1  C6 


HEBREW  AND  CHALDEE  TEXT-BOOKS. 

Green's  Grammar  of  the  Hebrew  Language 8vo,  8  00 

Elementary  Hebrew   Grammar 12mo,  1  26 

"       Hebrew  Chrestomathy 8vo,  2  00 

Gesenius's  Hebrew  and  Chaldee  Lexicon  to  the  Old  Testament 

Scriptures.     (Tregelles.) Small  4to,  half  morocco,  6  00 

Letteris's  Hebrew  Bible 8vo,  2  26 

16 


STACK 

SEP     73 


Los  Angeles 
T*1*8  book  "  DUE  on  the  last  date  stamped  below. 


MAR  2  9 1983 

i-    nC 


Fcrm  L9-100m-9,'52(A3105)444 


UC  SOUTHERN  REGIONAL  LIBRARY  FACILITY 


Library 


mm  mm . 

•••••-•••  r  i  " 


